<![CDATA[ Latest from Space.com in New-horizons ]]>

<![CDATA[ Latest from Space.com in New-horizons ]]> https://www.space.com Sat, 25 Oct 2025 12:00:00 +0000 en <![CDATA[ Here's where the James Webb Space Telescope and 4 other legendary spacecraft are in October's night sky ]]> Humanity's understanding of the solar system has evolved dramatically following the advent of spaceflight. Over the past seven decades, thousands of sophisticated spacecraft have been launched on ambitious missions to look down on our planet, explore the wonders of our star's domain, or venture into the interstellar realm beyond it.

The imagery and scientific data collection by these robotic explorers has inspired generations and forever altered how we view our planet and the universe around us. As a result, spacecraft such as the James Webb Space Telescope (JWST) and the venerable Voyager 1 probe are now household names, but how many of us actually know where they are as they beam back their precious data? How many of us have peered into the areas of space where they orbit or sail through the cosmos?

Read on to discover the approximate locations of five far-flung spacecraft in the October night sky. If you're new to exploring the stars, be sure to check out our roundup of the best smartphone astronomy apps, which use augmented reality tech to help guide you to the locations of everything from stars and nebulas to galaxies, wandering comets and spacecraft.

Find the locations of famous spacecraft in the October night sky

James Webb Space Telescope — 907,000 miles (1.46 million km) from Earth

An artist's impression of the James Webb Space Telescope flying through space against a star strewn deep blue sky featuring nebula clouds. — An artist's impression of the James Webb Space Telescope (Image credit: NASA, ESA, CSA, Northrop Grumman)

The James Webb Space Telescope launched on Christmas Day in 2021 on a mission to unravel the mysteries surrounding the creation and evolution of the cosmos. From its gravitationally stable vantage point at Lagrange Point 2, the JWST is tasked with peering into deep space to capture ancient light from the early universe and observe the formation of stars, protoplanetary systems and so much more. Check out our article detailing 12 amazing JWST discoveries to find out how the most powerful telescope ever launched is pushing the boundaries of astronomy.

A star map showing the path of the James Webb Space Telescope through October's evening sky. A yellow line simulates the path of the spacecraft alongside the stars of prominent constellations, which are joined by a blue line. The constellation Taurus is visible below the yellow line, with Orion beyond. The bright star Aldebaran is labelled in red in the constellation Taurus. — A skymap showing the location of the James Webb Space Telescope in October 2025. (Image credit: Created by Anthony Wood in Canva)

To find the JWST's position in the night sky, you'll first need to locate the red star Aldebaran, which can be found half way up the eastern sky above the familiar stars of the constellation Orion around midnight in October. Next, scan the region above until you find the diffuse, hazy light of the Pleiades star cluster. Webb will be located approximately 5 degrees — roughly the width of your three middle fingers held at arm's length against the night sky — below the Pleiades and will travel closer to Aldebaran and the other stars of the constellation Taurus as the month wears on.

Remember: this guide can show you the approximate location of the spacecraft, but it is impossible to actually spot them, as they are far too small and distant for even the most powerful of telescopes to resolve.

Parker Solar Probe — 91 million miles (147.6 million km) from Earth

An artist's impression of the Parker Solar Probe spacecraft facing and in close proximity to the sun. The disk of the star almost fills the frame, with swirling, fiery features and darker mottled spots present on its surface. — An artist's impression of the Parker Solar Probe approaching the sun. (Image credit: NASA/Johns Hopkins APL/Steve Gribben)

NASA's Parker Solar Probe became the first spacecraft to "touch" the sun on April 28, 2021, when it careened through the sun's outer atmosphere — also known as the corona — during the eighth of 24 planned close passes of our parent star. The probe has flown seven times closer to the sun than any spacecraft before while braving temperatures approaching 2,600 degrees Fahrenheit (1,300 degrees Celsius) to shed light on the plasma and magnetic field dynamics that drive the solar wind.

A star map showing the path of the Parker Solar Probe through October's evening sky. A yellow line simulates the path of the spacecraft alongside the stars of prominent constellations, which are joined by a blue line. The constellation Scorpius is visible below, with Sagittarius to the left and Ophiuchus above. — A skymap showing the location of the Parker Solar Probe in October 2025. (Image credit: Created by Anthony Wood in Canva)

The patch of sky containing the Parker Solar Probe can be found low in the southwestern sky at sunset in October, though you'll need a clear view of the horizon to spot it before it sets out of view! First, find the bright star Antares in the constellation Scorpius. The Parker Solar Probe's location is roughly 5 degrees to the upper left of the red supergiant star, with the constellation Ophiuchus shining above and the distinctive "teapot" asterism of the constellation Sagittarius to its left.

NASA's Juno spacecraft — 464.8 million miles (748 million km) from Earth

An artist's impression of the Juno spacecraft orbiting the gas giant Jupiter. The spacecraft has a hexagonal core from which three long, rectangular solar arrays extend. The arc of Jupiter's cloud surface is visible in the lower half of the image. — An artist's impression of the Juno spacecraft in orbit around Jupiter. (Image credit: NASA/JPL-Caltech)

The Juno spacecraft reached orbit around Jupiter in 2016 and has spent close to a decade — and several mission extensions — collecting data on both the gas giant and its many diverse moons. Its most recent mission extension expired on the same day that the current government shutdown came into effect. As a result, an ominous question mark hangs over the fate of the veteran spacecraft.

A star map showing the location of Jupiter in October's predawn sky alongside the stars of the constellation Gemini, which are joined by a blue line. Jupiter is visible to the lower right of the stars Castor and Pollux against a blue-black night sky, with the stars of the constellation Cancer below. — A skymap showing the location of NASA's Jupiter-orbiting Juno spacecraft in October 2025. (Image credit: Created by Anthony Wood in Canva)

To find Juno's location, you'll first need to locate the bright stars Castor and Pollux in the constellation Gemini, which twinkles high overhead in the eastern sky during the predawn hours in October. Jupiter will be easy to find as a bright "morning star" shining steadily to the lower right of Castor and Pollux. Juno is somewhere in orbit around the planet, far too small to be seen.

New Horizons — 5.88 billion miles (9.46 billion km) from Earth

An artist's impression of NASA's New Horizons spacecraft depicted against a black, star-studded sky. — An artist's impression of NASA's New Horizons spacecraft. (Image credit: NASA / JHUAPL / SWRI )

NASA's New Horizons spacecraft launched in January 2006 and after nine years travelling in space became the first human-made object to visit the dwarf planet Pluto in July 2015. The short-lived flyby transformed our understanding of the far-flung world, revealing surprising aspects of its composition, tenuous atmosphere and the nature of its largest moon, Charon. New Horizons later went on to study the Kuiper Belt object Arrokoth in 2019 and is now working to gather heliophysics data while enroute to interstellar space, which it is expected to reach sometime in the 2040s.

A star map showing the location of the New Horizons spacecraft in October's sunset sky close to the stars of the famous — A skymap showing the location of the New Horizons spacecraft in October 2025. (Image credit: Created by Anthony Wood in Canva)

The patch of night sky containing New Horizons can be found by locating the famous "teapot" asterism at the heart of the constellation Sagittarius above the southern horizon in the hours following sunset in October. From a dark sky location, you may see the glowing band of the Milky Way extending overhead and running through the "spout" of the stellar teapot!

Next, look above the trapezium of stars that form the handle of the asterism and locate the star Pi Sagittarii using your smartphone astronomy app. New Horizons' location is roughly 1 degree to the upper right of this little-known star.

Voyager 1 — 15.72 billion miles (25 billion km) from Earth

An artist's impression of the Voyager 1 spacecraft flying through space against a starry black sky. — An artist's impression of the Voyager 1 spacecraft in space. (Image credit: NASA/JPL-Caltech)

Voyager 1 is the most distant human-made object ever launched and became the first spacecraft to enter interstellar space when it passed beyond the heliosphere (a giant bubble in our solar system created by the solar wind that protects the planets from cosmic rays) in August 2012, following a tour of Jupiter and Saturn. The spacecraft carries with it one of NASA's famous Golden Records, which contain a selection of greetings, images and sounds from Earth curated as both a time capsule and a method of establishing friendly first contact with any who may later find the distant probe.

A star map showing the location of the Voyager 1 spacecraft in October's evening sky alongside the stars of prominent constellations, which are joined by a blue line. The location of the Voyager 1 spacecraft is denoted by a white circle embedded among the stars of the constellation Ophiuchus, which is pictured against a dark blue sky above a silhouetted western horizon, with the constellation Hercules to its right and Scutum to its left. — A skymap showing the location of the Voyager 1 spacecraft for October 2025. (Image credit: Created by Anthony Wood in Canva)

Voyager 1's location in the night sky can be found by first locating the stars of the constellation Ophiuchus close to the western horizon in the hours following sunset in October. Next, locate the highest point of light in the constellation — the binary star system Rasalhague — and its neighbor Kappa Ophiuchi to the lower right. Voyager 1's approximate position lies half way along the imaginary line connecting these two stellar giants.

Editor's Note: If you would like to share your astrophotography with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

]]> https://www.space.com/stargazing/heres-where-the-james-webb-space-telescope-and-4-other-legendary-spacecraft-are-in-the-night-sky-october-2025 7GqbStHEE68YACzs3B2QhU Sat, 25 Oct 2025 12:00:00 +0000 Fri, 24 Oct 2025 20:19:24 +0000 <![CDATA[ Pluto's hazy skies are making the dwarf planet even colder, James Webb Space Telescope finds ]]> The James Webb Space Telescope (JWST) has discovered that a hazy sky over frozen Pluto is helping to cool the dwarf planet's atmosphere, while at the same time giving methane and other organic molecules a kick out of Pluto's atmosphere, where some are subsequently being gathered up by Pluto's close companion, Charon.

The discovery of the haze was predicted back in 2017 by planetary scientist Xi Zhang of the University of California, Santa Cruz, to explain why Pluto's thin atmosphere is so leaky. Based on measurements from NASA's New Horizons spacecraft, which hurtled past Pluto and Charon in 2015, planetary scientist Will Grundy at the Lowell Observatory in Arizona calculated that Pluto's atmosphere is losing 1.3 kilograms (2.9 pounds) of methane to space every second, and about 2.5% of this methane is being intercepted by Charon, staining its poles red with organic chemistry. Nowhere else in the solar system do we see an atmosphere leaking onto a neighboring body.

The cause of this atmospheric escape was unknown, but Zhang reasoned that if Pluto's atmosphere contained a layer of haze, then this haze would absorb what little extreme ultraviolet light from the distant sun reaches Pluto, providing the energy to give molecules the nudge they need to escape into space.

Besides the haze heating the atmospheric molecules so that they can escape, Zhang also realized that the haze could have a cooling effect on Pluto's atmosphere — an effect that had previously been detected in Pluto's mesosphere, which is the third layer of the atmosphere above the virtually non-existent troposphere and the denser stratosphere.

Pluto's mesosphere is found between 20 kilometers and 40 kilometers (12.4 to 24.9 miles) high and reaches a maximum temperature of minus 163 degrees Celsius (110 Kelvin/minus 262 degrees Fahrenheit) before cooling at a rate of 0.2 degrees Celsius per kilometer, to a minimum of minus 203 degrees C (70 Kelvin/minus 334 degrees F).

The problem was that, until now, no haze had been detected on Pluto. Then along came the JWST.

A ring of blue over a dark background — Pluto's blue haze, produced by back-scattering from small particles in the atmosphere in a process known as Mie scattering. (Image credit: NASA/JHUAPL/SwRI)

Zhang had predicted that any atmospheric cooling spurred on by a layer of haze would result in thermal emission at mid-infrared wavelengths. Mid-infrared emission had been detected coming from the Pluto-Charon system before, going all the way back to Europe's Infrared Space Observatory in 1997, NASA's Spitzer Space Telescope in 2004, and Europe's Herschel Space Observatory in 2012. However, on each occasion, the telescope lacked the resolution to distinguish between Pluto and Charon and determine where the emission was coming from. But JWST, with its 6.5-meter (21.4 feet) primary mirror and Mid-Infrared Instrument (MIRI), is able to distinguish between Pluto and Charon. So Zhang, as part of a team led by Tanguy Bertrand of the Observatoire de Paris, was able to use JWST to detect the thermal mid-infrared emission from the long-elusive haze.

"We use the term 'haze' to describe layers of solid aerosols suspended high in an atmosphere," Bertrand told Space.com. "These aerosols scatter light and reduce visibility, forming a diffuse and semi-transparent layer."

Pluto's atmosphere is mostly nitrogen, with a smidgen of carbon dioxide and hydrocarbons such as methane, benzene, diacetylene and hydrogen cyanide. This atmosphere is exceptionally thin; the surface pressure is just 13 microbars, in comparison to Earth's surface pressure of about 1 bar. (One bar is equivalent to one million microbars.) And because of Pluto's low gravity, the upper atmosphere extends quite a long way from the surface, by several Pluto radii (the radius of Pluto is 1,188.3 kilometers, or 737 miles). All molecules need is a slight nudge to send them spinning out of the atmosphere, and the energy to give them that nudge comes from the sun.

"A significant fraction of the incoming solar extreme ultraviolet radiation is absorbed by the upper atmosphere, leading to heating that powers atmospheric mass loss," said Bertrand. "Atmospheric gases such as nitrogen and methane are responsible for absorbing radiation at these wavelengths."

But how can the haze alternatively cause both atmospheric heating and cooling?

"Cooling or heating depends on the haze properties, such as particle size, shape and composition — i.e., icy with hydrocarbon ice, or non-icy — which are not very well known," said Bertrand. "We are currently investigating this with state-of-the-art microphysical [i.e., on the scale of atoms and molecules] models."

The ability of the haze to cool or heat the atmosphere means that it therefore controls the balance of energy in Pluto's atmosphere, affecting global temperatures, atmospheric circulation and what passes for climate on the frigid dwarf planet. This climate system is dominated by cycles of sublimation and freezing out of molecular nitrogen, methane, and carbon monoxide, much of which hails from the deep glacier in Sputnik Planitia, which is the heart-shaped feature on the dwarf planet's surface.

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The newly published documents also confirm other exploration plans laid out in the skinny budget — for example, the cancellation of the Gateway moon-orbiting space station and the phaseout of the Space Launch System (SLS) rocket and Orion capsule.

These pieces of hardware have long been part of NASA's architecture for Artemis, its program of crewed moon exploration. The 2026 budget request eliminates SLS and Orion after they fly together on Artemis 3, a crewed landing mission targeted to launch in 2027.

They would be replaced by private vehicles developed via the new "Commercial Moon to Mars (M2M) Infrastructure and Transportation Program," which gets $864 million in the 2026 budget proposal.

It's unclear how much of this will actually come to pass, however; the budget request is just a proposal, which will not be enacted unless and until Congress approves it.

The Planetary Society, for one, doesn't think this will happen; it describes the budget request "as dead on arrival in Congress."

]]> https://www.space.com/space-exploration/trumps-2026-budget-would-slash-nasa-funding-by-24-percent-and-its-workforce-by-nearly-one-third bn5BbYMRfacBFVtqWNRoBC Sat, 31 May 2025 03:35:33 +0000 Sat, 31 May 2025 06:12:40 +0000 <![CDATA[ New Horizons' new map of the galaxy | Space photo of the day for April 30, 2025 ]]>

an artificial color map of a galaxy reveals the background scatter of ultraviolet light

This spectrograph map, generated from data collected by NASA's New Horizons probe, depicts the relatively uniform brightness of the ultraviolet "Lyman-alpha" background surrounding our Sun and its area of influence. (Image credit: Southwest Research Institute (SwRI))

A new study from the NASA New Horizons mission team at the Southwest Research Institute have resulted in a first-of-its-type map from the Milky Way galaxy in an ultraviolet wavelength, revealing details in the region around our solar system.

What is it?

This spectrograph map, generated from data collected by NASA's New Horizons probe, depicts the relatively uniform brightness of the ultraviolet (UV) "Lyman-alpha" background surrounding the sun and its area of influence.

"Understanding the Lyman-alpha background helps shed light on nearby galactic structures and processes," said Dr. Randy Gladstone with the Southwest Research Institute (SwRI) in Colorado. "This research suggests that hot interstellar gas bubbles like the one our solar system is embedded within may actually be regions of enhanced hydrogen gas emissions at a wavelength called Lyman alpha."

Lyman-alpha is a specific wavelength of UV light emitted and scattered by hydrogen atoms. It is useful when studying distant stars, galaxies and the interstellar medium, as it can help detect the composition, temperature and movement of these distant objects.

On this spectrograph map, the black dots represent approximately 90,000 known UV-bright stars in our galaxy.

Where is it?

New Horizons, which began as the first mission to flyby Pluto, collected baseline data about Lyman-alpha emissions during its initial journey to the small, icy world.

After the spacecraft's primary objectives at Pluto were completed, New Horizons' ultraviolet spectrograph (named "Alice") was used to make more frequent surveys of Lyman-alpha emissions as New Horizons traveled farther from the sun. These observations included an extensive set of scans in 2023 that mapped roughly 83% of the sky.

Why is it amazing?

Before this map was released, scientists theorized that a wall of interstellar hydrogen atoms would accumulate as they reached the edge of our heliosphere — the region of our galaxy where the solar wind from our sun reaches and interacts with the interstellar medium. New Horizons data saw nothing to indicate that this "wall" was an important source of Lyman-alpha emissions.

"These are really landmark observations, in giving the first clear view of the sky surrounding the solar system at these wavelengths, both revealing new characteristics of that sky and refuting older ideas that the Alice New Horizons data just doesn't support," said Dr. Alan Stern. the mission's principal investigator at SwRI. "This Lyman-alpha map also provides a solid foundation for future investigations to learn even more."

Want to know more?

Read more about New Horizons' mission after leaving Pluto and other recent research based on Lyman-alpha emissions. You can also find the scientific paper describing the SwRI map and its findings in The Astronomical Journal.

]]> https://www.space.com/space-exploration/new-horizons/new-horizons-new-map-of-the-galaxy-space-photo-of-the-day-for-april-30-2025 7Ktxfw4th3tLQSYZzSCQGh Wed, 30 Apr 2025 18:30:00 +0000 Wed, 11 Jun 2025 21:23:36 +0000 <![CDATA[ How the James Webb Space Telescope is helping size up tiny dwarf planets ]]> A surprising chemical difference between Pluto and Sedna, another dwarf planet in the distant Kuiper Belt, is helping scientists nail down their respective masses, a new study reports.

The Kuiper Belt is a region in space beyond the orbit of Neptune that's home to Pluto and most of the known dwarf planets, as well as some comets that are thought to be relics of the solar system's planet-formation era.

"Kuiper Belt objects are icy worlds [that] can tell us what conditions were like billions of years ago," explained study lead author Amelia Bettati, a researcher at Elon University in North Carolina. "Studying them helps scientists understand how planets formed and evolved."

Recent near-infrared spectroscopic studies carried out by the James Webb Space Telescope (JWST) found that Pluto contains both methane and ethane on its surface, key volatile molecules often found in the outer solar system and thought to be remnants from the time when the planets were forming. Sedna, which is less than half as wide as Pluto, was found to have only methane.

Related: What is the Kuiper Belt?

"We hypothesized that the reason for this difference is that Sedna is much smaller than Pluto, so its gravity is weaker," Bettati told Space.com. "This weaker gravity allows methane to escape into space over billions of years, while ethane, which is a heavier compound, stays behind."

While previous studies have identified a general boundary between objects that can hold onto these volatiles and those that cannot, the difference between Pluto and Sedna offers a new clue about how specific escape processes might shape the surface compositions of these distant objects. Sedna, being close to the mass threshold at which volatiles are lost, highlights the importance of understanding how certain chemicals are retained or lost, especially when comparing different Kuiper Belt objects.

"By studying how methane and ethane escape from Sedna, we calculated how massive Sedna must be to explain its current surface composition," said Bettati. "To explain the lack of methane but presence of ethane on Sedna, we must raise the minimum mass estimate for Sedna. This is important because it helps refine our understanding of Sedna's structure and history."

In their study, Bettati and co-author Jonathan Lunine, of NASA's Jet Propulsion Laboratory and the California Institute of Technology, modelled the levels of methane and ethane on Sedna. They verified their model's accuracy using two analogues: Comet 67P/Churyumov-Gerasimenko and Saturn's moon Enceladus.

Europe's Rosetta probe studied Comet 67P up close, and NASA's Cassini spacecraft gathered a wealth of data about Enceladus during the probe's time in the Saturn system.

"Both objects have well-defined measurements and are outer solar system objects, which justifies considering them analogues," said Bettati.

To figure out if enough methane and ethane escaped from these objects to no longer show up in their surface spectra, the scientists needed to estimate how much of these chemicals were originally trapped inside.

They did this under two different scenarios. One assumed that the ratio of methane and ethane to water ice is similar to what was measured on Enceladus, while another looked at the ratio found on Comet 67P during the winter. These comparisons helped them understand how much of these compounds may have been lost over time.

"[We used the] Jeans escape model, [which] is a kind of thermal escape driven by the atmospheric temperature, in which the fastest-moving molecules exceed the escape velocity, but the bulk of the molecules do not," Bettati said.

They also used another model known as hydrodynamic escape, which occurs when the bulk of the molecules are able to escape, rather than just those at the high-velocity end of the distribution. "Much of the atmosphere is in motion, escaping to space," said Bettati.

The models demonstrated that methane has remained stable on Pluto but escaped from Sedna due to its lower mass. Ethane, however, has stayed stable on both objects, even when using two different outgassing rates — 100% (indicating full release of volatiles) and 10% (a smaller release).

This result aligns with the observed surface spectra and provides a more accurate mass estimate for Sedna. The model also explains the absence of methane on another Kuiper Belt object known as Gonggong.

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"Like Sedna, Gonggong also lacks surface methane," said Bettati. "Since Gonggong is similar in size to Sedna, we believe methane must have escaped from it in a similar fashion. This suggests that smaller Kuiper Belt objects lose methane over time, while larger ones, such as Pluto, can hold onto it.

"If scientists know which gases are likely to be present on different Kuiper Belt objects, their loss rates, and their past compositions, they can better plan future missions."

These findings, in conjunction with JWST observations, will help scientists understand how atmospheres and surface compositions change in the Kuiper Belt and beyond.

"It highlights how JWST is revolutionizing our understanding of the most distant solar system bodies," Bettati said.

The new study was published in February in the journal Icarus.

]]> https://www.space.com/the-universe/how-the-james-webb-space-telescope-is-helping-size-up-tiny-dwarf-planets Pd8qLxCq6jtWsxNCbt2nbe Fri, 21 Mar 2025 20:00:00 +0000 Wed, 30 Apr 2025 17:39:37 +0000 <![CDATA[ Hubble Telescope discovers a new '3-body problem' puzzle among Kuiper Belt asteroids (video) ]]>

NASA's Hubble Space Telescope has discovered that a system of asteroids in the distant Kuiper Belt may be triplets, not twins as previously suspected.

If so, the stable trio of icy space rocks would be just the second example of three gravitationally bound space rocks found in the Kuiper Belt, the doughnut-shaped region of icy bodies that lurks out beyond the orbit of Neptune.

The discovery could also challenge our understanding of how Kuiper Belt objects (KBOs) form.

illustration of two asteroids in deep space, with a shiny silver space telescope as an inset in the lower left of the frame — An illustration of the 148780 Altjira system of two or maybe three asteroids. Inset: the Hubble Space Telescope (Image credit: NASA, ESA, Joseph Olmsted (STScI))

If it is confirmed as a triplet, the system — designated 148780 Altjira — could offer scientists a chance to improve their models of how three gravitationally bound bodies move through space together.

This puzzle, known as the "three-body problem," has been a challenge since Isaac Newton published his work "Principia" in 1687.

"The universe is filled with a range of three-body systems, including the closest stars to Earth, the Alpha Centauri star system, and we're finding that the Kuiper Belt may be no exception," team leader Maia Nelsen, a physics and astronomy graduate of Brigham Young University in Provo, Utah, said in a statement.

Related: What is the Kuiper Belt?

Three's company in the Kuiper Belt

Astronomers Dave Jewitt and Jane Luu discovered the first icy body in the Kuiper Belt, known as 1992 QB1, in 1992. Since then, a further 3,000 KBOs have been cataloged.

Astronomers estimate that several hundred thousand more KBOs measuring over 10 miles (16 kilometers) in diameter could lurk in this icy donut, which begins around 2.8 billion miles (4.5 billion km) from the sun.

The Kuiper Belt is thought to stretch as far as 4.6 billion miles (7.4 billion km) from the sun, which is around 50 times the distance between Earth and our star. The Altjira system sits in the middle of the Kuiper Belt, at around 3.7 billion miles (6.0 billion km) from the sun, or about 40 times the distance between Earth and the sun.

orbital diagram showing the positions of five different spacecraft in the distant kuiper belt — A diagram showing the Kuiper Belt and the voyage of NASA's New Horizons probe, which visited the KBO Arrokoth, also known as 2014 MU69. (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory)

The Hubble Space Telescope images initially seemed to show that the Altjira system was composed of two KBOs located about 4,700 miles (7,600 km) apart.

When the team conducted repeated observations of the Altjira system object's unique co-orbital motion, however, they found the inner object is actually two bodies. These KBOs are so close together that they can't be distinguished individually from such a great distance away.

"With objects this small and far away, the separation between the two inner members of the system is a fraction of a pixel on Hubble's camera, so you have to use non-imaging methods to discover that it's a triple," Nelsen said.

It took 17 years of data from Hubble and the Keck Observatory in Hawaii to observe orbital changes in the Altjira system and make this determination. The data was added to various modeling scenarios, with the most likely explanation being a triple-body system.

"Other possibilities are that the inner object is a contact binary, where two separate bodies become so close they touch each other, or something that actually is oddly flat, like a pancake," Nelsen added.

Of 40 multiple-body systems identified in the Kuiper Belt, this is just the second identified composed of more than two objects. The researchers think these aren't outliers and there are more multi-asteroid systems out there in the outer reaches of the solar system, waiting to be discovered,

a lumpy looking reddish-brown space rock — Arrokoth, the so-called "space snowman," another prominent KBO. (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Roman Tkachenko)

The Hubble observations of the Altjira system, which suggest it has a third occupant, support a theory of KBO creation that involves the direct gravitational collapse of matter in the disk of material surrounding the infant sun around 4.5 billion years ago.

This direct collapse pathway is similar to the formation process of stars, albeit it on a vastly smaller scale. Star formation from dense patches of gas and dust can also result in two and three-body systems.

The alternative KBO creation theory, which sees these icy space rocks created from collisions between larger bodies, would not create a three-body arrangement as the Altjira system appears to be.

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The Altjira system joins the dwarf planet Pluto and the "space snowman" Arrokoth, a contact binary composed of two touching space rocks, as the most heavily studied bodies in the Kuiper Belt.

NASA's New Horizons probe flew by Pluto in 2015 and Arrokoth in 2019. There's no visit to Altjira in the works, but the researchers behind the new study hope that detailed remote observations of the system will be possible in the future.

Particularly exciting will be forthcoming observations of Altjira conducted by the James Webb Space Telescope during its third year of operations.

"Altjira has entered an eclipsing season, where the outer body passes in front of the central body," Nelsen said. "This will last for the next 10 years, giving scientists a great opportunity to learn more about it." \

The new study was published on Tuesday (March 4) in The Planetary Science Journal.

]]> https://www.space.com/space-exploration/hubble-space-telescope/hubble-telescope-discovers-a-new-3-body-problem-puzzle-among-kuiper-belt-asteroids-video eeYfNBXQ5dPR4DSSNMGPd5 Wed, 05 Mar 2025 22:00:00 +0000 Wed, 05 Mar 2025 18:36:51 +0000 <![CDATA[ Leaving Pluto in the dust: New Horizons probe gearing up for epic crossing of 'termination shock' ]]> NASA's New Horizons spacecraft conducted the first and only flyby of the Pluto system, culminating at the closest approach of that distant world in July 2015.

Sailing onward, the probe carried out a Jan. 1, 2019 flyby of Arrokoth, a Kuiper Belt Object, or KBO, located in a region of space beyond Neptune called the Kuiper Belt. There are scads of other icy worlds residing in the Kuiper Belt, celestial leftovers from the formation of our solar system.

For New Horizons, the gathering of more exploration science is, pun intended, on the horizon.

Invaluable observations

Late last year, a study by the U.S. National Academies titled "The Next Decade of Discovery in Solar and Space Physics: Exploring and Safeguarding Humanity's Home in Space" observed that "key challenges are to keep receiving the invaluable observations from the New Horizons and Voyager spacecraft, which are the only means to gain firsthand knowledge of the environment in the outer heliosphere and outside the heliospheric bubble."

That report also noted that "moving outward, the boundary of the solar system where the sun's influence wanes and is replaced by the interstellar environment, there is much to be discovered."

The heliospheric decadal report is important for several reasons, said New Horizons Principal Investigator Alan Stern of the Southwest Research Institute in Boulder, Colorado."It's a completely independent validation by the community about how important and unique the New Horizons science is to that field," he told Space.com.

New Horizons is gearing up to cross the sun's "termination shock," Stern said, where the subsonic solar wind slows down and becomes subsonic as it rams into the interstellar medium.

up-close spacecraft photo of a brownish-red two-lobed deep-space object that looks a lot like a snowman — This composite image of the primordial Kuiper Belt object Arrokoth was compiled from data obtained by NASA's New Horizons spacecraft as it flew by the object on Jan. 1, 2019. The image combines enhanced color data (close to what the human eye would see) with detailed high-resolution panchromatic pictures. (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute//Roman Tkachenko)

Guessing game

Though New Horizons is now in hibernation mode, the spacecraft is still collecting heliophysics data around the clock, Stern said, squirreling that data into onboard solid state memory — basically a big flash drive.

"We went into hibernation mode on October 3 of last year. We exit that mode on April 2 of this year. When we wake up, we'll transmit the backlogged New Horizons data down to NASA's Deep Space Network," said Stern.

"But actual crossing of the termination shock, the timing is a guessing game. No one can fully predict that, but it could potentially be as early as 2027 … and we want to be on guard then so we don't miss it," Stern noted.

Meanwhile, New Horizons is in perfect health. "There's nothing broken on the spacecraft and the seven instruments that it's carrying," he added. "They are working super-well, as well as when they were launched."

Diagram depicting the heliosphere, an enormous magnetic bubble in space carved out by the solar wind, with the current positions of two nasa spacecraft noted — Diagram depicting the heliosphere, an enormous magnetic bubble in space carved out by the solar wind. (Image credit: NASA/Walt Feimer)

Fuel gauge reads low

But New Horizons is low on propellant. "And that just means we have to be miserly with that fuel. Any fuel we spend is not going to get us to a new flyby of a KBO, so it reduces the odds of a flyby," said Stern.

Being tight on fuel means that Stern has adopted a new title to go along with principal investigator: "Fuel hoarder in chief."

Regarding the spacecraft's power and data transmission, the long-distance craft is good to go. Its nuclear power generating system will perhaps last into 2050, Stern advised.

So, could New Horizons perform a flyby of another far-flung KBO?

Possibly, if the mission gets some help from Earth-based observatories, particularly the soon-to-come online Vera C. Rubin Observatory. Rubin's detection of KBOs along an attainable New Horizons flight path would "significantly raise the odds of getting a flyby," Stern added. "But it's a needle in the haystack search," he added, "even using the world's best tools."

Unanswered questions

Meanwhile, a New Horizons heliophysics team consisting of about a dozen scientists and engineers are intently focused on spacecraft measurements taken in the outer heliosphere, said Andrew Poppe of the Space Sciences Laboratory at the University of California, Berkeley. He is a co-investigator and heliophysics science lead on the New Horizons mission.

That team is gearing up for New Horizons' crossing of the termination shock, one of the key outer boundaries between our heliosphere and interstellar space, Poppe told Space.com.

"Both Voyager spacecraft crossed this boundary and revealed a wealth of new physics," he said. "However, due to certain limitations in the Voyager instrumentation, key questions regarding a population of ions known as 'pickup ions' were left unanswered."

Poppe added that, since the Voyager measurements, it has become increasingly clear that these pickup ions may in fact dominate the transfer of energy and momentum across the termination shock.

photo of a middle-aged man in a dark, long-sleeved shirt sitting at a table, with a model of a spacecraft in the background — New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute. (Image credit: NASA/Joel Kowsky)

First-ever measurements

Fortunately, New Horizons carries key instrumentation — the Solar Wind Around Pluto (SWAP) and Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) — that will conduct the first-ever measurements of these critical pickup ions in the outer heliosphere and across the termination shock.

"With this in mind, the New Horizons heliophysics team has been planning out specific instrument observing modes, planning data downlink budgets (no easy feat from 60-plus astronomical units!), and engaging the broader outer heliospheric theoretical community to prepare for the groundbreaking measurements that New Horizons will return in the near future," Poppe said.

Overall, the New Horizons team is humbled to follow in the footsteps of Voyager, said Poppe, "but extraordinarily excited to contribute first-of-a-kind measurements of the outer boundaries of the heliosphere we call 'home.'"

Historic encounter

The crossing of the termination shock itself could be as short as 10 minutes, said Pontus Brandt, the New Horizons project scientist at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland.

"But there will likely be multiple crossings as the shock moves back and forth over the spacecraft for multiple days and surely will be another historic encounter for New Horizons," said Brandt.

"The data from the termination shock encounter will be a treasure trove for space physicists worldwide who are eager to understand how this vast boundary works," Brandt told Space.com. "All these discoveries from pioneering missions like Voyager and New Horizons teach us how little we know about what lies beyond, and pave the way for a future dedicated Interstellar Probe mission," he said.

Essence of exploration

Brandt underscored another possible New Horizons exploration bonus.

"I think we may have only seen the tip of the iceberg of the Kuiper Belt, which could be much more extended than we ever could imagine," Brandt said.

"Dust hits measured by the spacecraft just keep being elevated, defying all our expectations of a 'Kuiper Cliff.' One must always give oneself the opportunity of discovery," Brandt added, "the essence of exploration."

In a few years, New Horizons could very well find itself in the midst of a new region of the Kuiper Belt, Brandt suggested. That would be "a historic opportunity for planetary science with important implications for understanding exoplanetary systems."

— NASA celebrates New Horizons' historic Pluto flyby in 2015 with awesome new videos

— Far beyond Pluto: What's next for NASA's New Horizons probe?

New surprises

As a "first responder" and record title holder of a spacecraft, New Horizons has already chalked up history-making observations as the first spacecraft to explore Pluto and its moons up close. Also, after a nine-year journey, the probe passed its second major science target, zipping by the KBO Arrokoth in 2019, the most distant object ever inspected up close.

New Horizons' findings are taking center stage at an upcoming 10th anniversary of the Pluto flyby science meeting now being planned for this July at APL, which designed, built, and operates the New Horizons spacecraft and manages the mission for NASA.

"We're pulling together everything that has been learned since the flyby of New Horizons. And not just from the spacecraft, but also from the Hubble Space Telescope, the James Webb Space Telescope, and from Earth-based observations, too," Stern said. "So stand by. I'm betting on some new surprises!"

]]> https://www.space.com/space-exploration/new-horizons/leaving-pluto-in-the-dust-new-horizons-probe-gearing-up-for-epic-crossing-of-termination-shock yroo7pTvTfroxAAVKcBv3k Wed, 19 Feb 2025 22:00:10 +0000 Thu, 20 Feb 2025 12:51:07 +0000 <![CDATA[ 2nd Kuiper Belt? Our solar system may be much larger than thought ]]> A brand-new group of frozen objects, orbiting the sun out beyond the distant Kuiper Belt, has been spotted by the Subaru telescope, working with NASA's New Horizons mission to find new targets for the spacecraft to investigate.

"If this is confirmed, it would be a major discovery," said Fumi Yoshida, from the University of Occupational and Environmental Health Sciences and the Planetary Exploration Research Center, Chiba Institute of Technology, in a statement.

Subaru, which is an 8-meter (26-foot) telescope atop Mauna Kea in Hawaii, has been working with New Horizons since its 2006 launch toward Pluto, which the spacecraft flew by in 2015. Since then, New Horizons has been blazing a trail through the Kuiper Belt, which is a ring-shaped region of icy cometary bodies beyond the orbit of Neptune at distances between 33 and 55 astronomical units (AU). An astronomical unit is equivalent to Earth's average distance from the sun, which is 149.6 million kilometers (93 million miles).

When Subaru began searching for Kuiper Belt objects in 2004 as potential targets for New Horizons to either visit up close or to watch with its cameras from a distance after encountering Pluto, the telescope was faced with a problem. At the time, Pluto and the area of the outer solar system to which New Horizons was headed was in the constellation of Sagittarius, which has the dense center of the Milky Way as a backdrop, making it hard to pick out Kuiper Belt objects from all the background stars. At the time, Subaru identified just 24 Kuiper Belt objects, all of which were too far away for New Horizons to reach or view with its cameras after leaving Pluto. (Arrokoth, a Kuiper Belt object that New Horizons visited on New Years' Day 2019, was found by the Hubble Space Telescope.)

Related: What is the Kuiper Belt?

Now, however, Pluto and that part of the solar system has moved away from the backdrop of the Milky Way into a sparser region of the night sky. With its Hyper Suprime-Cam (HSC), Subaru has discovered 239 Kuiper Belt objects since 2020. Most of these are regular Kuiper Belt objects, but a smattering seem to be very special indeed.

"The most exciting part of the HSC was the discovery of 11 objects at distances beyond the known Kuiper Belt," said Yoshida.

This new group of objects isn't a mere extension of the Kuiper Belt. There appears to be a gap between 55 AU and 70 AU where no objects have yet been found, and then a second belt — let's call it "Kuiper Belt 2" — between 70 and 90 AU, which is as far out as 13.5 billion kilometers (8.4 billion miles) from the sun. For comparison, Neptune lies at 30 AU and New Horizons is currently 60 AU from the sun, while NASA's Voyager 1 and Voyager 2 probes are 164.7 and 137.6 AU from the sun, respectively — out in interstellar space.

A black and white graph labeled heliocentric distance, with black bars mostly on the left side. — A graph that shows the number of Kuiper Belt objects versus their distance from the sun. The 11 new objects seem to form a second Kuiper Belt, with a gap between 55 and 70 AU. (Image credit: Wesley Fraser)

The architecture of the solar system, including the asteroid belt and the Kuiper Belt, was determined by the processes that formed the planets, including how the young Jupiter migrated through the system, scattering smaller bodies far and wide.

"I think the discovery of distant objects and the determination of their orbital distribution are important as a stepping stone to understanding the formation history of the solar system, comparing it with exoplanetary systems, and understanding universal planet formation," said Yoshida.

The discovery of this new population of bodies is not entirely out of the blue. The Student Dust Counter instrument on board New Horizons keeps detecting impacts from dust particles, though the rate of impacts should be decreasing as New Horizons departs the Kuiper Belt. The continued presence of dust suggests that it is being produced by a population of bodies farther out. In addition, New Horizons has witnessed unexplained stellar occultations — when an object passes in front of and briefly blocks the light of a distant star — that could be the product of objects in this newly discovered, more distant 'Kuiper Belt 2.'

Furthermore, observations of protoplanetary disks around other stars, such as those seen by ALMA, the Atacama Large Millimeter/submillimeter Array in Chile, clearly show extended regions and numerous belts and gaps in the region beyond where the Kuiper Belt is in our solar system.

"Our solar system's Kuiper Belt long appeared to be very small in comparison with many other planetary systems, but our results suggest that idea might just have arisen due to an observational bias," said Wes Fraser of the National Research Council of Canada, who led the new findings. "So maybe, if this result is confirmed, our Kuiper Belt isn't all that small and unusual after all compared to those around other stars."

Because the Kuiper Belt had seemed small, one theory had been that the solar nebula that formed our planetary system had also been smaller than normal. The discovery of this Kuiper Belt 2 suggests that was not necessarily the case.

"The primordial solar nebula was much larger than previously thought, and this may have implications for studying the planet formation process in our solar system," said Yoshida.

— What cosmic object 'Arrokoth' can tell us about our solar system's formation

— Could an 'Earth-like' planet be hiding in our solar system's outer reaches?

Astronomers will continue to use Subaru to track the 11 objects in this new belt to better define their orbits. Given they were found in a small region of space, they probably are only the tip of the iceberg and hint at a much larger population. Their discovery is further evidence that there is still much to be discovered in the extreme depths of the outer solar system, including the possibility of more dwarf planets and even the hypothesized Planet Nine.

"This is a groundbreaking discovery revealing something unexpected, new and exciting in the distant reaches of the solar system," said Alan Stern, who is the principal investigator on the New Horizons mission. "This discovery probably would not have been possible without the world-class capabilities of the Subaru Observatory."

The findings are set to be published in the Planetary Science Journal, and are currently available as a preprint.

]]> https://www.space.com/second-kuiper-belt-solar-system-larger-than-thought HELCdjoTMT9TkpoiSj9H9n Wed, 18 Sep 2024 19:30:00 +0000 Wed, 30 Apr 2025 17:37:58 +0000 <![CDATA[ Just how dark is the universe? NASA's New Horizons probe gives us best estimate yet ]]> Space looks black, but just how dark is it?

It's a deceptively simple question that has puzzled astronomers since the 1960s. Now, thanks to data from NASA's New Horizons probe, they have arrived at the best-yet estimate of how dark — or rather, bright — deep space is: 100 billion times dimmer than the sunlight we see on Earth.

That's the amount of ambient, universe-permating glow from the births and deaths of trillions of galaxies and their countless stars ever resided in our universe. This vanishingly faint light is called the cosmic optical background (COB), and can be thought of as the visible equivalent of the cosmic microwave background (CMB) radiation, the light left over from the universe's creation.

"If you hold up your hand in deep space, how much light does the universe shine on it?" study lead author Marc Postman, an astronomer at the Space Telescope Science Institute in Baltimore, said in a statement. "We now have a good idea of just how dark space really is."

Precise measurements of the COB allows astronomers to study how and where galaxies and stars formed across the universe's 13.8-billion-year history. But the remnant glow is so imperceptible that even advanced telescopes struggle to distinguish it from unrelated light sources in the inner solar system, including sunlight scattered by the swarm of debris around Earth and countless specks of interplanetary dust.

"All attempts to measure the strength of the COB from the inner solar system suffer from large uncertainties," said study co-author Tod Lauer, an astronomer at the National Science Foundation's NOIRLab in Arizona.

New Horizons, however, zoomed past Pluto in July 2015 on its one-way trek out of the solar system and is now 5.5 billion miles (8.7 billion kilometers) from Earth — far enough away to witness the darkest possible "skies" and to collect the most accurate measurements to date of the faint background glow.

In the summer of 2023, the spacecraft scanned its surroundings using its onboard camera, gathering snapshots of two dozen pockets of the universe while pointing at high galactic latitudes, away from nearby bright stars and the Milky Way's blinding core. The probe's main body also shielded the sensitive camera such that even the dimmest sunlight couldn't directly reach it, according to the same statement.

While analyzing the probe's images, Lauer and his colleagues deducted light generated by dust in the halo that the Milky Way sits in, leaving them with a precise estimate of the cosmic optical background: roughly 11 nanowatts per square meter per a width of sky about 130 times the moon's diameter. The estimate is consistent with the number of galaxies formed since the Big Bang, the researchers say.

"Importantly, we also found that there is no evidence for significant levels of light produced by sources not presently known to astronomers," Postman said in the statement.

That's a relief to the researchers, whose initial estimates in 2021 suggested that the COB may be brighter than expected, leaving them to wonder whether there are any exotic, as-yet-undiscovered light sources contributing to the cosmic light.

"In our previous paper, we found there was as much light we couldn't account for as light we could measure," Postman told Astronomy.com. "The real 'gotcha' was that we simply weren't as familiar with the distribution of dust in the Milky Way as we should have been."

— New Horizons Pluto probe notches 3 new discoveries in outer solar system

— Far beyond Pluto: What's next for NASA's New Horizons probe?

This time, the team was able to reference recent maps of galactic dust put together by the European Space Agency's Planck spacecraft and correct for the previously overestimated dust-scattered light.

"Looking outside the galaxies, we find darkness there and nothing more," Lauer said in the statement.

New Horizons, which is currently studying the little-explored Kuiper Belt in an extended mission mode, faced an uncertain future last August after NASA considered disbanding the mission's original science team, but agency officials later decided to continue the mission as-is for at least another five years, until 2028. Mission team members have said the probe has enough fuel to continue flying through at least 2040.

This research is described in a paper published Aug. 28 in The Astrophysical Journal.

]]> https://www.space.com/universe-darkness-estimate-new-horizons inzbJast6TJkQzgLjTCneh Tue, 10 Sep 2024 12:00:50 +0000 Tue, 10 Sep 2024 12:28:43 +0000 <![CDATA[ We could float effortlessly in Pluto's subsurface ocean ]]> Pluto's surface, fitting for a world whose surface shivers at a cryogenic -364 F (-220 C), is frozen solid.

But beneath that nitrogen ice may lie a subsurface ocean of liquid water. A recent study suggested what that ocean might look like: It might be deeper than Earth's crust and denser than Earth's seawater.

It may seem odd to search for liquid water on a world as frigid and distant as Pluto. But in data from New Horizons, scientists have found a few clues hinting at a liquid water layer beneath Pluto's surface. For one, Pluto lacks a bulge at its equator, a feature that is less likely to form if a body has a liquid interior. Secondly, Pluto's icy surface appears to have fractured due to stretching over time, which could have been caused by liquid water freezing underneath the nitrogen ice on its surface, as water is one of the few substances that expands when it freezes.

Most strikingly, some scientists believe that Pluto holds cryovolcanoes that spew out water vapor or even solid water ice. That water has to come from somewhere — and a layer of liquid water beneath Pluto's crust would fit the description.

Researchers at Washington University in St. Louis and the Lunar and Planetary Institute in Houston set about constructing a model of what that liquid layer might look like. In particular, they wanted to match Sputnik Planitia — a heart-shaped lowland basin on Pluto's surface thought to be the aftermath of an impact. So, the researchers tried different configurations of ocean thickness and water density that would result in the Sputnik Planitia criss-crossed with cracks that New Horizons observed.

"We estimated a sort of Goldilocks zone where the density and shell thickness is just right," said Alex Nguyen, a graduate student at Washington University in St Louis and one of the authors, in a statement.

Their calculations indicated that a Plutonian ocean would most likely be around 25 to 50 miles (40 to 80 kilometers) thick, and about 8 percent denser than Earth seawater. That is about as dense as the Great Salt Lake.

— NASA extends New Horizons mission through late 2020s

But the idea of a Plutonian ocean is still controversial. Scientists don't know enough about Pluto to know if the evidence really points to liquid water or if it's just circumstantial. Most recently, a study simulating the origin of Sputnik Planitia suggested that the heart-shaped basin was most likely to have formed if Pluto had a solid interior.

So, until a successor to New Horizons lets us revisit Pluto, what lies beneath the world's surface will remain cloaked in shadow.

Nguyen and co-author Patrick McGovern published their work in the journal Icarus on February 15.

]]> https://www.space.com/pluto-ocean-thickness-new-horizons vrVQz7hrNAsimEfF2KGH95 Thu, 23 May 2024 20:59:39 +0000 Thu, 23 May 2024 18:41:13 +0000 <![CDATA[ Pluto's heart-shaped scar may offer clues to the frozen world's history ]]> When NASA’s New Horizons mission flew past Pluto in 2015, it gave humanity our first glimpse of a colossal depression on the isolated world. It's named Sputnik Planitia. Comparable in size to the country of Mexico and dominating one of Pluto’s hemispheres, Sputnik Planitia is likely the result of an impact — but few impact craters come in Sputnik Planitia's unique pear-like shape.

How Sputnik Planitia formed remains unknown, but researchers have now painted a possible picture of its origins. It's possible, they say, that a body about the size of Switzerland crashed into Pluto long ago, at a shallow angle. If true, this picture would also hint at what Pluto's interior may look like under its cryogenic surface.

Related: Why is Pluto not a planet?

"Most thought Sputnik Planitia was of impact origin, but nobody had been able to explain its distinctive pear shape," Harry Ballantyne, an astronomer at the University of Bern in Switzerland, told Space.com.

Sputnik Planitia's shape and colossal size — roughly 2,000 kilometers long (1,243 miles long) and 1,600 kilometers wide (994 miles wide) — are not the only reasons planetary scientists have looked at it with curiosity. Whatever created this formation managed to carve out a dent as deep as s 4 kilometers (2.5 miles); and at the bottom of the chasm appears to be a frozen expanse of nitrogen ice. Gravity ought to have slowly rotated Pluto such that the dent and its missing mass ended up at one of Pluto's poles — but, oddly enough, Sputnik Planitia remains around the equator.

One popular theory suggested that Sputnik Planitia was actually a hint of a global ocean buried under Pluto's surface. After a massive impact, liquid water from the ocean might have risen to fill the gap, which would have then been iced over with a nitrogen coating — explaining why Sputnik Planitia stayed on the equator. Still, some scientists remained unconvinced.

"I had never bought into the idea that Sputnik ending up on the equator requires a global ocean," Erik Asphaug, an astronomer at the University of Arizona, told Space.com. "In my view it's much easier to explain it if you start and end with a solid body that can sustain this kind of splat."

So, Asphaug, Ballantyne and their colleagues set about conducting three-dimensional simulations to learn what circumstances might have given rise to Sputnik Planitia. The feature's strange shape was a hint that the dent's creator struck Pluto obliquely, rather than head-on. That led them to simulate a 700-kilometer-wide (435-mile-wide) object — a ball of ice and rock — striking a Pluto-like world. This object was made to exhibit a rocky core within a water-ice shell too, and the impact was imparted at a shallow 30-degree angle. Indeed, not only did this scenario lead to a pear-shaped crater, but the team's simulations indicated that the core of the impactor remained buried under Sputnik Planitia, giving it the extra mass it needed to remain on the equator.

— Our solar system map may need an update — the Kuiper belt could be way bigger

— NASA extends New Horizons mission through late 2020s

The authors say that future research is still needed to expand on these concepts, both to understand how Sputnik Planitia evolved over billions of years and how collisions work in this distant corner of the solar system.

"There's still a lot to learn about planetary collisions," Adeene Denton, a planetary scientist at the University of Arizona and another of the paper’s authors, told Space.com. "And for the Kuiper Belt in particular, there are many uncertainties for what happens when icy and rocky bodies collide."

Pluto's interior may help us understand those dynamics at last, but for more definite answers, we may have to wait for another mission. Although New Horizons' visit to Pluto was a remarkable feat, the probe did not do any more than simply fly by, meaning that the mission, very literally, only scratched the former planet's surface. A future mission may be able to orbit Pluto and probe its interior by, for instance, measuring the world's gravitational field.

"We need the kind of geophysical data that's been collected around the Moon and Mars that have allowed us to determine the internal structure of those bodies in such detail," Denton told Space.com. "There's a lot of information to be gained about Pluto's interior, and orbiting Pluto is the best way to do it."

The researchers published their work in the journal Nature Astronomy on April 15.

]]> https://www.space.com/pluto-heart-shaped-scar-history-frozen-world dwXNKYkPPrBBNbwpuXeyDS Tue, 23 Apr 2024 10:00:01 +0000 Tue, 23 Apr 2024 13:29:34 +0000 <![CDATA[ Our solar system map may need an update — the Kuiper belt could be way bigger ]]> NASA's New Horizons mission, which encountered Pluto in 2015 is now riding through the deepest depths of the Kuiper Belt, is encountering a cosmic dust storm that hints there may be more going on in the outermost reaches of the solar system than we imagine.

Space is filled with dust formed of tiny particles just microns — millionths of a meter — in size. Much of the dust in our solar system is leftover residue from the formation of the planets, which was a violent affair that saw a multitude of objects smash into one another. Today, this ancient dust is also joined by fresh dust sputtered off the surfaces of asteroids and comets by micrometeorite impacts. This dust content, both fresh and ancient, gives rise to the enigmatic "Zodiacal light." The dust extends into the farthest reaches of the solar system. Astronomers still are not entirely sure of the make-up of this final frontier.

The Kuiper Belt (or the Kuiper–Edgeworth Belt, named after astronomers Gerard Kuiper and Kenneth Edgeworth, who independently proposed its existence) is so far away, and its icy inhabitants are so small and faint, that it wasn't until 1992 that the first Kuiper Belt Object (KBO) beyond Pluto was discovered. That discovery was made by University of Hawaii astronomers Dave Jewitt and Jane Luu. But since then, thousands of KBOs have been spotted, and astronomers have tentatively been able to begin mapping the outer solar system.

Beyond the Kuiper Belt is the Scattered Disk, populated by KBOs that have been scattered from the Kuiper Belt by gravitational tides coming from the solar system's outermost planet, Neptune. Objects in the Scattered Disk tend to have highly elliptical orbits that are steeply inclined to the plane of the solar system and can go out to hundreds of AU's from the sun. One AU, or astronomical unit, is equal to the distance between Earth and the sun.

Far beyond the Kuiper Belt and the Scattered Disk is the Oort Cloud, a vast spherical region of frozen objects extending over a light-year from the sun. While its distance means that the Oort Cloud has never been directly observed, scientists know it exists because the orbits of long-period comets can be traced back to there.

Now, however, new findings from New Horizons threaten to upend much of what we thought we knew about the outer solar system to begin with.

"New Horizons is making the first direct measurements of interplanetary dust far beyond Neptune and Pluto, so every observation could lead to a discovery," astronomer Alex Doner of the University of Colorado, Boulder said in a statement.

The distance between the outer edge of the Kuiper Belt and the sun was thought to be about 50 astronomical units ( one AU is also equal to 149.5 million kilometers, or 93 million miles.) On Jan. 1, 2019, New Horizons encountered the KBO named Arrokoth, which sits at a distance of 44.5 AU from the sun; today, New Horizons is at a distance of 58.25 AU from the Sun, having passed the 50 AU mark in April of 2021. Over the past five years, New Horizons should have sailed over the edge of the Kuiper Belt. With KBOs separated by millions of miles, however, New Horizons wouldn't visually notice that it had left them behind. Instead the sign would be a drop-off in levels of interplanetary dust.

Yet, the spacecraft's Venetia Burney Student Dust Counter (SDC), named after the little girl who named Pluto in 1930, has not observed this drop-off. In fact, there's as much dust as ever out there, bewildering astronomers.

Diagram showing the probe's trajectory in the solar system. — The trajectory that New Horizons is taking through the outer solar system. Arrokoth was encountered at 44.6 AU. (Image credit: NASA/Johns Hopkins APL/SwRI)

The SDC is mounted on the leading face of the New Horizons spacecraft. It consists of 14 plastic film detectors, each 14.2 by 6.5 centimeters (5.6 by 2.6 inches) in size and just 28 microns thick. A dozen of the detectors are exposed to space, while the other two are shielded so that they can act as reference detectors, recording any events not related to dust impacts to help rule out false positives. Whenever a dust particle strikes one of the detectors, the impact leaves a little pit in the plastic film that subtly alters the way their surfaces conduct electricity.

One possibility is that the excess dust was actually produced closer to the sun and was blown out of the Kuiper Belt thanks to the pressure of sunlight acting on the particles. However, Doner's team has deemed this theory unlikely. Instead, a more enticing possibility is favored, they say.

There may simply be more to the Kuiper Belt than astronomers had realized.

The continued presence of dust implies New Horizons is still within the Kuiper Belt, and that the Kuiper Belt is far more extensive than anyone knew, stretching across billions of miles farther from the sun than our maps presently estimate.

It's not just the dust counts telling us this. Astronomers have been using machine learning algorithms to search observations made by the 8.2-meter Subaru Telescope on Mauna Kea in Hawaii, and the Victor M. Blanco Four-Meter Telescope at the Cerro Tololo Inter-American Observatory in Chile to hunt for more icy objects out there that New Horizons could investigate. They've so far found 154 objects in the direction that New Horizons is headed, including about 20 that the spacecraft will come within a few million miles of, close enough for some rudimentary observations. Yet some of those 154 objects appear to be located beyond the Kuiper Belt, and not on the kind of eccentric orbit suggestive of the Scattered Disk, but in the ecliptic plane that's also shared by the Kuiper Belt.

Are they members of a wider Kuiper Belt, or perhaps even a second belt?

"The idea that we might have detected an extended Kuiper Belt — with a whole new population of objects colliding and producing more dust — offers another clue in solving the mysteries of the solar system's most distant regions," said Doner.

An illustration of New Horizons in space. It has a white satellite dish type disk in front and a golden body. On the bottom and on the sides there are some grey squares. — An artist's impression of NASA’s New Horizons spacecraft. The Student Dust Counter is on the underside of the vehicle as seen from this perspective. (Image credit: NASA/Johns Hopkins APL/SwRI/Steve Gribben)

— What cosmic object 'Arrokoth' can tell us about our solar system's formation

— Could an 'Earth-like' planet be hiding in our solar system's outer reaches?

New Horizons is sailing through uncharted waters. Only four spacecraft have passed this way before — Pioneer 10 and 11, and Voyager 1 and Voyager 2; none were equipped with a dust counter like New Horizons.

While the Pioneers are long since inactive and with the Voyager 1 spacecraft beginning to falter, New Horizons has enough fuel and power to survive well into the 2040s, when it could be well beyond 100 AU from the Sun. By the time its power dwindles, it will likely have completely redrawn the map of the outer solar system.

The new results from the SDC were published on Feb. 1 in the Astrophysical Journal Letters.

]]> https://www.space.com/solar-system-map-kuiper-belt-extended-new-horizons-nasa FPwMGXWdkn5mPEBZzDaNFC Fri, 23 Feb 2024 13:00:52 +0000 Thu, 22 Feb 2024 22:56:11 +0000 <![CDATA[ Pluto's 'almost twin' dwarf planet Eris is surprisingly squishy ]]>

Close to 18 years ago, astronomers spotted a miniature, icy world named Eris billions of miles beyond Neptune. But unlike its dwarf planet cousin Pluto — which New Horizons promoted to a rich, dynamic world after its visit in 2015 — Eris has not had any robotic visitors. It is so far away from Earth, in fact, that it shows up in observations just as a single pixel of light.

All in all, scientists know very little about what happens on Eris.

Though what we do know is Eris is known to have an atmosphere that freezes and snows onto the surface below, thanks to its place near the edge of the solar system. It's about 68 times farther from the sun than Earth is. And now, new models based on data from an array of radio telescopes in Chile have revealed more about Eris. Heat leftover from the dwarf planet's birth seems to be oozing out and slowly flexing its icy surface.

The process is causing Eris to behave less like a solid, rocky planet and "more like a soft cheese or something like that," study co-author Francis Nimmo of the University of California Santa Cruz said in a statement. "It has a tendency to flow a bit."

While a lot still remains unknown about Eris, it is considered an "almost perfect" twin of Pluto — both dwarf planets are nearly exactly the same size. Actually, when it was first spotted in 2005, it appeared to be slightly bigger than Pluto, triggering a debate among scientists. This had led the International Astronomical Union (IAU) to clarify its definition of a planet and demote Pluto to a dwarf planet. It was thanks to this contention in the scientific community that the IAU in 2006 named the dwarf planet Eris, after the Greek goddess of discord.

For the latest study, Nimmo and his colleague Mike Brown, a Caltech astronomer who had led the discovery of Eris in 2005 and is best known as the man who killed Pluto, estimated the mass for Eris' very small moon Dysnomia. Eris and its satellite are mutually tidally locked, which means both face the same way toward each other. Scientists think this is because the tiny moon "raises" tides on Eris, causing the dwarf planet to spin down over 4.5 billion years.

The new findings show Eris likely has a rocky core enveloped by a convecting icy shell.

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"The rock contains radioactive elements, and those produce heat. And then that heat has to get out somehow," said Nimmo. "So as the heat escapes, it drives this slow churning in the ice."

He and Brown suspect the surface of Eris should be "pretty smooth" as any surface features will likely be erased by flowing ice.

"So it would be nice to get some measurements of what shape Eris is because if it's very irregular, that would not agree with our model."

This research is described in a paper published Nov. 15 in the journal Science Advances.

]]> https://www.space.com/pluto-twin-dwarf-planet-eris-squishy z42Sg2ADhRFcV4VsMYVMWi Tue, 05 Dec 2023 01:00:01 +0000 Thu, 07 Dec 2023 12:42:48 +0000 <![CDATA[ New Horizons' Alan Stern will fulfill a lifelong dream on Virgin Galactic spaceflight this week ]]> When Alan Stern launches to suborbital space this week on Virgin Galactic's fifth commercial flight, he'll accomplish the goal of a lifetime. But it won't be all play — Stern will be working during almost the entire mission.

That won't dilute the joy of fulfilling his childhood dream, however. Growing up in the Apollo era, Stern watched flights to the moon launch with some regularity. Like many of his generation, he expected crewed spaceflight to become routine, expecting many more trips to the moon and, in relatively short order, voyages to Mars as well. Instead, he watched as only a handful of people climbed out of Earth's atmosphere.

Stern, a planetary scientist at the Southwest Research Institute (SwRI) in Boulder, Colorado and principal investigator of NASA's New Horizons mission to Pluto and the outer solar system, will soon join their ranks. On Thursday (Nov. 2), he will take a brief trip to suborbital space on Virgin Galactic's Galactic 05 mission.

"I've done a lot of things over the last 30 years that have led me to be prepared," Stern told Space.com. To be so close to heading into space is "really gratifying [and] a little surreal," he said.

a shirtless man with electrodes attached to his chest gives a thumbs-up while on a treadmill in a white-walled room. — Alan Stern undergoes a physical during astronaut candidate-selection training on Oct. 31, 1995. (Image credit: NASA)

Preparation

Preparing for spaceflight isn't like packing for a family vacation. As part of his training for Galactic 05, Stern has completed three centrifuge sessions and three high-performance jet flights.

The jet flights weren't like his previous research trips, during which he performed airborne astronomy on board F-18 Hornets and other combat aircraft. Instead, the flights reached high levels of acceleration, or Gs, to help prepare the body for the rapid speeds achieved at launch.

"I can tell you, at the end of those flights, it's just like that scene in the original 'Top Gun' movie in the locker room," Stern said. "You're raining sweat."

But he doesn't expect his actual flight to be quite so physically demanding. "Just like athletes, you train harder than the event," Stern said.

A lifetime accomplishment

Stern's fast-moving training isn't the only way he has prepared for spaceflight. He has been working toward that goal throughout his career.

"As a young engineer, and then as a young scientist, I did everything I could think of to make myself a top candidate to be a NASA engineer," he wrote on Oct. 23, in a piece for The Space Review.

That included scuba diving, traveling to the South Pole, becoming a commercial pilot and even working as a state-certified Emergency Medical Technician. He applied six times to become a NASA space shuttle mission specialist and was at one point approved to fly as a shuttle payload specialist, though he was later replaced by another researcher.

Over the last decade, Stern has been encouraging scientists to travel into space via commercial space flight. Since 2010, Stern has helped to organize the Next-Generation Suborbital Researchers Conference, which brings together hundreds of suborbital researchers, educators, flight providers, spaceport operators and others.

Stern has also campaigned tirelessly for the research and education marketplace in suborbital flight.

"When Virgin and Blue Origin started their business, they had only one interest, and it was flying tourists," Stern said. "I started talking to them about flying researchers and educators. They both do that now."

"All the suborbital flight providers in this commercial era are doing research in addition to tourist flights," he said.

a person in a helmet gives a thumbs-up from inside a jet cockpit, with the ground far away in the background. — Planetary scientist Alan Stern, associate vice president of Southwest Research Institute’s Space Science Division, undergoes flight training aboard an F-104 jet in preparation for his Nov. 2, 2023 flight aboard the Virgin Galactic commercial spacecraft VSS Unity on a suborbital space mission. (Image credit: Starfighters, Inc.)

For Stern's short flight, he has eight objectives laid out by SwRI. Most of those will help set the stage for his next suborbital flight, which will be funded by NASA. That upcoming flight will be purely research, Stern said.

While in the air, he will be working to familiarize himself with how the actual experience differs from training simulations, a process that will make future research flights flow more smoothly. He'll be wearing a bioharness modeled after a design flown on more than two dozen space shuttle missions, according to his flight team member Dan Durda, also of SwRI. The harness will measure his blood pressure and heart rate and compare those figures to data from his centrifuge runs and zero-g flights, as well as to the Virgin-Galactic-provided biomedical band.

As preparation for his upcoming NASA flight, Stern will also carry a functional mockup of the camera that he will carry on his second trip into space.

But all of the objectives aren't strictly business. One thing Stern will be doing is to "mitigate the overview effect distractions" — a fancy way of saying, getting a look out the window now so it won't distract him on the next flight.

"When we're there to get a very specific job done…we pretty much can't 'afford' the 'distractions' of the rest of this amazing experience," Durda told Space.com by email. "So, getting that all 'out of the way,' so to speak, is an important risk-reduction aspect of a first flight like this."

'A damn good time'

— Virgin Galactic launches 1st mother-daughter team and 1st Olympian to space on 2nd commercial flight (video)

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Does Stern have any concerns about his upcoming trip?

"You mean, other than I could be killed?" he said.

He acknowledged that the risk is higher than it would be on a commercial airline flight. At the same time, with more than 24 zero-g flights under his belt, Stern has experience with potentially dangerous situations.

His bigger fear is smaller than that. In the week before his flight, Stern flew to Boston for a meeting with more than 100 people to discuss the New Horizons mission. "I don't want to get something from somebody and be sick next week," he said.

That fear is well founded. During Apollo 13, NASA astronaut Thomas Kenneth Mattingly was kept from launching into space due to exposure to German measles, which he never contracted. (Mattingly later flew on Apollo 16.)

While exposure wouldn't be enough to keep Stern from going to space, being sick likely would affect his flight capability. "I'm masking a fair amount," Stern said.

After several decades of trying to get into space, what is Stern most excited about?

"Accomplishing the objectives and having a damn good time," he said.

]]> https://www.space.com/virgin-galactic-alan-stern-suborbital-research-flight qf992VcWZbp7iePLAztquL Tue, 31 Oct 2023 10:00:04 +0000 Tue, 31 Oct 2023 11:33:47 +0000 <![CDATA[ Could Neptune's largest moon swing a spacecraft into the planet's orbit? ]]> The only spacecraft to visit Neptune was the Voyager 2 probe, which spent just a few precious minutes in the vicinity of this mysterious world during its historic flyby tour of the outer solar system in the 1980s. It's been over 40 years since that mission launched. And while space agencies around the world have developed dozens of probes, landers and rovers in the decades since, none have visited the solar system's outermost planet, let alone orbit it.

Planetary scientists have long been interested in a return visit to Neptune, but the planet is so distant that an orbiter or lander mission is next to impossible. While the New Horizons spacecraft has visited the dwarf planet Pluto, that was a brief fly-by mission. So far, the most distant orbiter that we've sent has been to Saturn.

Neptune is so far away that it's difficult to fathom: It sits roughly 30 times farther from the sun than Earth does. To put that into context, Jupiter is only five times farther from the sun than Earth is. It takes years for an orbiter to reach Jupiter, and Neptune is five times farther away. While Voyager 2 took 12 years to fly past Neptune, it zoomed by without stopping, quite a very different mission profile. New Horizons flew past Neptune and its moon Triton in 2014 from a distance of about 2.45 billion miles (3.96 billion kilometers), but also just zoomed past the planet. Placing a spacecraft in orbit around the planet is quite a different matter, and remains infeasible with current technologies.

One problem with a return mission to Neptune is that a flyby focused solely on that world does not provide significant bang for the buck. Without the lucky alignment available to missions in the 1970s and '80s, we'd have to spend even more fuel to send a probe in that direction, and we wouldn't get that much more science than we did decades ago.

The next logical step after a successful flyby mission is an orbiter, but the extreme distance to Neptune poses significant challenges. We have no clear way to haul a large enough orbiter to the Neptune system, pack enough fuel to allow it to slow down and do it all in a reasonably short amount of time.

However, researchers have shared a radical new idea for how to overcome these challenges: Use the thin atmosphere of Triton, Neptune's largest moon, to capture a spacecraft.

a bluish moon with a large grey mass across its surface — NASA's Voyager 2 spacecraft captured dark streaks produced by geysers visible on the icy surface of Triton's south polar region. (Image credit: NASA/JPL)

In a paper appearing in the preprint database arXiv, the researchers pointed out that in 2022, NASA successfully completed the Low-Earth Orbit Flight Test of an Inflatable Decelerator (LOFTID). The goal of that program was to develop an inflatable shield to protect a spacecraft as it descended through Earth's atmosphere and slow the craft so it didn't crash upon landing.

The researchers proposed to aim a future Neptune orbiter at Triton and use a LOFTID-like apparatus, known as an aeroshell, to slow the spacecraft. They found that the atmosphere of Triton, despite having less than 1/70,000 the air pressure of Earth's atmosphere, could sufficiently slow a spacecraft and allow it to enter into a captured orbit around Neptune. Additionally, they could change the angle of the aeroshell to tweak the orbiter's alignment and fine-tune the course to get it into the perfect orbit.

To get it right, the orbiter would have to get as low as 6 miles (10 kilometers) above the surface of Triton. That's not much higher than a typical intercontinental flight, but because Triton doesn't have any seriously large mountain ranges (the tallest known peaks are barely a kilometer tall), there's very little risk of a catastrophic collision with the surface.

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Similar ideas have been proposed for using an aeroshell to insert an orbiter around Saturn using its moon Titan, but Titan has a much thicker atmosphere, making the job a lot easier. Although Triton's atmosphere is incredibly thin, the moon sits relatively far away from Neptune, meaning the spacecraft would not be traveling as quickly, and would not have to reduce its speed as much, to be captured.

The researchers estimate that, using this aeroshell technique, a mission to Neptune could take as little as 15 years, which is far shorter than any other current mission ideas would allow. With current approaches, an orbiter would need to pack so much fuel for use in slowing itself down at Neptune that it would never be able to reach a high velocity, making the trip extremely long.

And there's a bonus to the plan: It would give us an up-close view of Triton, which is one of the strangest objects in the solar system and likely a captured Kuiper Belt object. We'd get to see this odd world from a vantage point of only a few kilometers above the ground, thus delivering some great extra science.

]]> https://www.space.com/neptune-triton-spacecraft-orbit-capture-assist 8MBhQafC4eMr3QaxzUEH5A Thu, 19 Oct 2023 16:00:45 +0000 Wed, 18 Oct 2023 21:23:51 +0000 <![CDATA[ What cosmic object 'Arrokoth' can tell us about our solar system's formation ]]> A new study from researchers at the Southwest Research Institute has unearthed a fascinating discovery about Arrokoth, a trans-Neptunian object made famous by the New Horizons probe on New Year’s Day in 2020.

It would appear that the two lobes of Arrokoth are dotted with mounds, each about five kilometers (3.1 miles) across. Those mounds, which give the lobes a slightly raspberry-like appearance, share roughly the same shape, size, color and albedo (how reflective the material is). Such similarity strongly indicates the mounds are disparate objects of a common origin that clumped together at some point to form large parts of the two lobes of the entire 18-kilometer wide (11.2 miles) body of Arrokoth.

"It's amazing to see this object so well preserved that its shape directly reveals these details of its assembly from a set of building blocks all very similar to one another," Dr. Will Grundy, a co-investigator of the New Horizons mission from the Lowell Observatory, said in a statement.

Arrokoth is a planetesimal in the Kuiper Belt, a vast stretch of space beyond Neptune that holds remnant building blocks of the solar system leftover from our cosmic neighborhood's formation. Because such planetesimals are believed to have slowly come together and eventually form the planets we see today, scientists are quite interested in studying these objects' characteristics.

The two lobes of Arrokoth, the team realized, are strongly suggestive of a "streaming instability model" of formation, where very gentle collisions, occuring at essentially walking speed, allow smaller objects to accumulate into larger ones. The new research opens up new questions though, primarily around the nearly uniform "building blocks" that make up the individual lobes.

"Similarities including in sizes and other properties of Arrokoth’s mound structures suggest new insights into its formation," said Alan Stern, principal investigator of the New Horizons mission and lead researcher on a new study about the discovery, said in the statement. "If the mounds are indeed representative of the building blocks of ancient planetesimals like Arrokoth, then planetesimal formation models will need to explain the preferred size for these building blocks."

Stern recently presented the paper at the 55th Annual Division for Planetary Sciences meeting in San Antonio.

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These findings actually bolster the streaming instability model in the first place, suggesting that objects gently accumulated to form Arrokoth at minimal collision speeds in a specific region of the solar nebula undergoing gravitational collapse. "The mounds' uniform sizes and attributes could redefine the very understanding of Arrokoth's formation," Stern said. He emphasized that if these mounds indeed mirror the building blocks of ancient planetesimals like Arrokoth, scientists might need to rethink theories about planetesimal formation in general.

With missions like NASA’s Lucy targeting Jupiter’s Trojan asteroids and ESA’s comet interceptor on the horizon, there is bound to be a lot more interest in how these objects are composed. Like Arrokoth, the subjects of those endeavors are planetesimals left over from the earliest days of the solar system.

"It will be important to search for mound-like structures on the planetesimals these missions observe to see how common this phenomenon is, as a further guide to planetesimal formation theories,” Stern said.

A paper on these results was published Sept. 26 in The Planetary Science Journal.

]]> https://www.space.com/arrokoth-kuiper-belt-planetesimal-formation-new-horizons QjRyacgkBYSpffHZfiVrhD Mon, 09 Oct 2023 12:00:37 +0000 Fri, 06 Oct 2023 19:48:47 +0000 <![CDATA[ NASA extends New Horizons mission through late 2020s ]]> NASA's New Horizons spacecraft will be able to keep exploring its exotic environs for at least another five years.

The agency announced on Friday (Sept. 29) that it will keep New Horizons' lights on while it's still zooming through the Kuiper Belt, the expansive ring of icy bodies beyond Neptune's orbit.

"The New Horizons mission has a unique position in our solar system to answer important questions about our heliosphere and provide extraordinary opportunities for multidisciplinary science for NASA and the scientific community," Nicola Fox, associate administrator for NASA's Science Mission Directorate in Washington, said in a statement on Friday. (The heliosphere is the big bubble of magnetic fields and charged particles that the sun blows around itself. Beyond it lies interstellar space.)

"The agency decided that it was best to extend operations for New Horizons until the spacecraft exits the Kuiper Belt, which is expected in 2028 through 2029," Fox added.

New Horizons launched in January 2006, on a mission to provide the first-ever up-close looks at Pluto, the Kuiper Belt's most famous resident. The spacecraft delivered, zooming past the dwarf planet in July 2015 and revealing a world of stunning diversity and beauty.

And the probe kept cruising along, on an extended mission that centered on a flyby of another Kuiper Belt object (KBO) — the 21-mile-wide (34 kilometers) Arrokoth. That encounter went swimmingly as well, returning great imagery and intriguing science. For example, New Horizons' observations suggest that Arrokoth formed via a very gentle merger of two smaller objects, mission team members said.

But the mission's future became murky this year. NASA extended New Horizons' mission through 2024, but proposed a big shift after that — a move to the Heliophysics Division, from Planetary Science. New Horizons' principal investigator, Alan Stern, objected to this idea, arguing that the best scientific return would come from staying the course, allowing the probe to continue studying the little-explored Kuiper Belt.

Artist's impression of NASA's New Horizons spacecraft. (Image credit: NASA/JHUAPL/SwRI)

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The newly announced mission extension appears to be a compromise of sorts. It will be funded primarily by Planetary Science but jointly managed by that division and Heliophysics.

Beginning in 2025, New Horizons will focus on gathering heliophysics data — but team members can still hold out hope for another KBO encounter.

"While the science community is not currently aware of any reachable Kuiper Belt object, this new path allows for the possibility of using the spacecraft for a future close flyby of such an object, should one be identified," NASA officials said in the same statement. "It also will enable the spacecraft to preserve fuel and reduce operational complexity while a search is conducted for a compelling flyby candidate."

Stern seems happy to have secured at least five more years of New Horizons operations. "I want to thank everyone who supported us in getting #NASA to continue the exploration of the Kuiper Belt by its @NASANewHorizons spacecraft — You did it!" he wrote via X (formerly known as Twitter) on Sunday (Oct. 1).

NASA spent $9.5 million on New Horizons in fiscal year 2022, according to Space News. The agency is still working on how to pay for the mission's next five or so years.

"As a starting point, funding within the New Frontiers program (including science research and data analysis) will be rebalanced to accommodate extended New Horizons operations, and future projects may be impacted," NASA officials wrote in the same statement. (New Frontiers is NASA's program of medium-cost missions; New Horizons was the first New Frontiers project to get off the ground.)

Additional extensions are possible, if the resources and will are there; New Horizons has enough nuclear fuel remaining to continue flying through at least 2040, mission team members have said.

]]> https://www.space.com/nasa-extends-new-horizons-mission-late-2020s TmHXLqvyWrtMzCov7x8NDg Tue, 03 Oct 2023 12:00:50 +0000 Mon, 02 Oct 2023 22:10:42 +0000 <![CDATA[ NASA's New Horizons mission faces an uncertain future (op-ed) ]]> For 17 years, the New Horizons spacecraft has hurtled at unprecedented speed through the solar system. Launched in 2006, it flew past Pluto in July 2015, returning the first close-up images of the planet and its moon. Then, in 2019, the probe reconnoitered the Kuiper Belt Object (KBO) Arrokoth. Both encounters returned astonishing images and a treasure trove of transformative data.

With its budget being trimmed for 2024, NASA is making some weighty decisions... and one includes drastically trimming New Horizons funds by replacing the current science staff with a new team in an effort to save about $3 million—a rounding error in terms of the planetary science budget.

The principal investigator of the mission from its earliest days, Dr. Alan Stern, is not happy about the situation. "New Horizons is the only spacecraft in the Kuiper Belt, and the only one currently planned to go there. We have valuable new Kuiper Belt observations, and a search for a new flyby target, still to complete every year until we leave the Belt. Quitting this exploration prematurely, after spending nearly $1 billion to get New Horizons to the Kuiper Belt, seems to many of us to be tragically mistaken, a poor use of taxpayer money, and a lost scientific opportunity that can never be recovered from."

As it stands, New Horizons will exit the Kuiper Belt around 2028 and should continue operating until 2050. "The spacecraft continues flying in excellent health today, returning data from the outer reaches of the solar system and preparing for a possible encounter with another KBO. Recent events, however, threaten the continued progress of this Kuiper Belt mission," Stern added.

While we can expect cuts across a variety of NASA programs and missions, the current New Horizons budget is about on par with other long-serving veterans of deep space explorations, Voyagers 1 and 2. We're talking well under $10 million per year, which in government terms is a pittance ... especially when you consider the expense of getting the spacecraft where they are today. That is a sunk cost, and the potential, congoing science returns from the mission are the dividends.

When New Horizons flew past Pluto, it returned an unprecedented look at the previously mysterious world and its large moon, Charon. Previous to this, the best images of Pluto came from the Hubble Space Telescope and were mere smudges just a few pixels across. The imagery and data returned from New Horizons upended many assumptions about not just Pluto and Charon, but also about the outer solar system.

"New Horizons literally wrote the book on Pluto and its system of moons. Before New Horizons, almost nothing was known. Today the New Horizons spacecraft and team have made Pluto one of the best known worlds in the solar system," Stern said.

New Horizons' next adventure was in the Kuiper Belt, the region beyond Neptune's orbit which is filled with rock and ice left over from the earliest era of the solar system. Stern's team targeted the KBO 486958 Arrokoth, which turned out to be another golden opportunity.

"Arrokoth may have been more important than our discoveries at Pluto," Stern commented. "For decades, there have been two warring computer models about how planets got their start and planetesimal formation. One was through high-speed collisions in their orbit around the sun, and the other was through local collapse clouds with very gentle collisions." After a thorough examination of Arrokoth, the latter model was validated. "It turns out these objects collided at very low speeds, more like how you might walk into a wall as opposed to supersonic impacts. When we saw Arrokoth up close, we realized from its shape and general surface geology that it had been built through gentle accretion," he added. Only though direct observation could this argument have been settled.

If NASA ends up cutting funding to this modestly budgeted mission, a new team would be installed—presumably one with no direct experience in outer solar system operations—with the focus shifted to low-level data gathering about heliophysics, the distant plasma environment of the sun. This reduced mission would utilize just a small fraction of the spacecraft's ongoing science capability.

"We've been in flight for going on 18 years, and we have every prospect of flying as long as the Voyagers," now going on 46 years, Stern said. "At that point we would be well beyond Kuiper Belt exploration and into interstellar space." Notably, while the Voyagers are currently exploring that same interstellar region, they are doing so with ancient 1970s technology and instruments that are being shut down as they age out, with mission operations scheduled to be slimmed down until they cease within a decade or so. "New Horizons should be able to continue until at least the middle of the 21st century," Stern added, "with nearly state-of-the-art instrumentation that will be capable of shifting our view of interstellar space just as it has changed our understanding of Pluto and KBOs. But none of that justifies curtailing the current exploration of the Kuiper Belt."

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Neptune will appear to reside in the constellation of Aquarius during September, shining at magnitude +7.8. It'll be modestly high in the southern sky for northern hemisphere observers, sitting just two degrees south of the celestial equator. Uranus is expected to be brighter at magnitude +5.7 and much better placed in the constellation of Aries.

Although resolving atmospheric details through the eyepiece will require telescopes with larger apertures, you can also pick out both planets with 10x50 binoculars and resolve them as tiny disks through an 8-inch telescope. So even if you can't contribute to NASA's atmospheric monitoring endeavor, you can still join in and observe the planets from your backyard, or better yet, local dark site.

Observers are encouraged to post their images with supporting info to social media using the hashtag #NHIceGiants, where the New Horizons team will collate them all and select the best for inclusion in the study.

]]> https://www.space.com/nasa-new-horizons-probe-uranus-neptune kBWdhFxhjpkoXVuiPB5bYi Wed, 16 Aug 2023 19:30:20 +0000 Wed, 16 Aug 2023 17:38:45 +0000 <![CDATA[ NASA may shift New Horizons Pluto probe to sun-studying mission ]]> The future of NASA's New Horizons Pluto probe is uncertain following debates at NASA over how best to use the spacecraft.

New Horizons launched in 2006, and conducted a flyby of Pluto in 2015, which gave humanity the clearest images of the dwarf planet to date. In 2019, in the far stretches of the solar system beyond Pluto, New Horizons was able to observe a Kuiper Belt object (KBO) known as Arrokoth, the most distant object ever explored by humans.

Now, the probe's future beyond the end of 2024 is being called into question as NASA decides whether to keep the probe focused on its original mission or shift it to another scientific mission altogether.

The controversy surrounding NASA's New Horizons probe boiled to the surface on May 4 at a meeting of the Outer Planets Assessment Group (OPAG) in Laurel, Maryland, according to SpacePolicyOnline.com editor Marcia Smith who published notes from the meeting on Twitter.

The gathering included New Horizons principal investigator Alan Stern, who expressed bewilderment over NASA's decision to approve only two of the three-years proposed for the spacecraft's second extended mission. Stern says his team suggested a cross-disciplinary approach to New Horizons' remaining time in the Kuiper Belt (KB), distributed between NASA's planetary science, astrophysics and heliophysics divisions. (Heliophysics is a branch of astronomy devoted to studying the sun and its influence on the rest of the solar system.)

ripples in ice on the surface of Pluto — The surface of Pluto's icy Sputnik Planum seen in a photo captured by NASA's New Horizons spacecraft during its close flyby of the dwarf planet on July 14, 2015. (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

Instead of remaining in NASA's planetary science division, the mission will have to compete in a separate senior review for the heliophysics division beginning in 2025. Stern called decision is "shortsighted," arguing that a shift in New Horizons' focus to heliospheric science could sacrifice the study of new KBOs.

A slide Stern shared as part of his presentation reads that the shift "also goes directly against the Decadal Survey that sent New Horizons to the KB, quoting: Its 'value increases as it observes more KBOs and investigates the diversity of their properties.'" He also stressed New Horizons' favorable Planetary Senior Review results, which cited 23 "major strengths" and only 1 "major weakness."

Curt Niebur, lead scientist for flight programs in the planetary science division, also attended the OPAG meeting. According to Smith, Niebur pointed out that NASA's decision was based on the Senior Review, which also concluded the probability of another KBO flyby to be improbable, calling it a "needle-in-a-haystack" issue. The return on planetary science research from New Horizons, NASA concluded, is far less than the astrophysics and heliophysics investigations the spacecraft can accomplish moving forward.

In a separate tweet, Smith described the interaction between Stern and Niebur as "heated".

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Through his frustration, Stern also made it clear that this wasn't an end to New Horizons outright. "NASA is not planning to turn the spacecraft off, simply to terminate the planetary mission and to dismiss the planetary team," Stern said. And on that, the two agreed. Niebur stated turning off New Horizons was never part of the Senior Review recommendation, and that the agency is looking for the best path forward for the spacecraft.

Traveling at over 36,000 mph (57,936 km/h), and covering more than 300 million miles per year, New Horizons won't exceed the vastness of the Kuiper Belt until 2028.

]]> https://www.space.com/new-horizons-pluto-probe-debate c93tgVN5H6SY45vhuMhsz4 Tue, 09 May 2023 12:00:26 +0000 Mon, 08 May 2023 22:06:35 +0000 <![CDATA[ Jupiter missions: Past, present and future ]]> Jupiter, the largest planet in the solar system, is currently being studied by NASA's Juno probe.

But Juno is just one of nine spacecraft to have visited the gas giant, with several other pioneering missions on the horizon, namely the European Space Agency's (ESA) JUICE and NASA's Europa Clipper.

Here we explore every mission to have visited the Jovian neighborhood and also introduce those scheduled to embark on the journey in the next year or two.

Related: Latest Jupiter news

Past Jupiter missions

Pioneer 10

NASA's Pioneer 10 was the first spacecraft ever to make it as far as Jupiter. The probe launched on March 2, 1972, on an ambitious mission to study the asteroid belt, Jupiter's atmosphere and the outer solar system.

About a year and a half after its launch, Pioneer 10 reached the Jovian neighborhood.

The probe cruised within 124,000 miles (200,000 kilometers) of the gas giant's turbulent atmosphere and took measurements of Jupiter's magnetosphere, radiation belts, magnetic field and interior. Pioneer 10's measurement of the intense radiation in the Jovian environment was used to help design the Voyager and Galileo spacecraft that would study the gas giant in even more detail, according to NASA.

Pioneer 11

A sister ship to its predecessor, Pioneer 11 launched on April 6, 1973. The spacecraft became the second to fly through the asteroid belt and passed Jupiter in December 1974.

Pioneer 11 took many detailed images of Jupiter's Great Red Spot as well as the planet's poles and also measured the mass of the Jovian moon Callisto. Pioneer 11 then became the first spacecraft to encounter Saturn in July 1979.

Voyager 1

Voyager 1 launched on Sept. 5, 1977, and flew past Jupiter in March 1979. The spacecraft captured more than 18,000 images of the gas giant and its moons.

Voyager 1's first pictures of Jupiter beamed back to Earth in April 1978, when the probe was 165 million miles (266 million km) from home. To NASA's surprise, in March 1979 Voyager 1 spotted a thin ring circling the giant planet. It found two new moons as well — Thebe and Metis. Additionally, Voyager 1 sent back detailed pictures of Jupiter's big Galilean moons (Io, Europa, Ganymede and Callisto) as well as Amalthea.

Among Voyager 1's discoveries was the presence of volcanic activity on Io, showing that, like planets, moons can have active interiors.

In 2012, Voyager 1 entered interstellar space, becoming the first human-made object ever to do so. The spacecraft is now approximately 14.6 billion miles (23.5 billion km) away from our planet, making it Earth's farthest spacecraft. Voyager 1 is currently zipping through space at around 38,000 mph (17 kilometers per second), according to NASA's Jet Propulsion Laboratory.

Voyager 2

Voyager 2 launched on Aug. 20, 1977, about two weeks before its twin spacecraft Voyager 1. But the probe reached the Jovian neighborhood later than its twin, arriving in April 1979.

Voyager 2's arrival allowed NASA to take valuable comparison shots of Jupiter and its moons. It captured changes in the Great Red Spot and also resolved some of the moon's surfaces in greater detail.

Voyager 2 took pictures of many of Jupiter's satellites. Among its most spectacular findings were pictures of the icy moon Europa. The probe snapped detailed photos of the icy moon's cracks from 128,000 miles (205,996 km) away and revealed no change in elevation anywhere on the moon's surface. Voyager 2 also captured an image of Adrastea, an exceptionally small moon, about 19 miles (30.5 km) in diameter at its smallest estimate.

Voyager 2 followed its sister ship into interstellar space in 2018.

Galileo

The Galileo spacecraft was the first mission sent to orbit Jupiter. It launched on Oct. 18, 1989, and arrived in orbit around the gas giant in December 1995.

While in orbit, Galileo dropped an atmospheric probe, which measured the temperature, wind speeds and pressure in Jupiter's clouds as it descended.

Galileo's mission was extended to study Jupiter's moons Io, Europa, Ganymede, and Callisto. The spacecraft revealed a trove of secrets about these satellites, including the presence of a salty ocean under Europa's surface and an iron core and magnetic field on Ganymede.

When Galileo was almost out of fuel, NASA deliberately sent the spacecraft on a suicide plunge into Jupiter on Sept. 21, 2003. The sacrifice, the agency said, was necessary to protect Europa — whose subsurface ocean could contain life.

Ulysses

The Ulysses spacecraft launched on Oct. 6, 1990, as part of a joint venture between NASA and ESA to study the sun in more detail.

The probe flew by Jupiter in February 1992 in a gravity assist maneuver to set the probe on track to solar polar orbit.

During the Jupiter flyby, Ulysses gathered helpful measurements of Jupiter's intense magnetic field and radiation environment.

Cassini-Huygens

The Cassini-Huygens probe (a NASA-ESA-Italian Space Agency mission) is best known for its study of Saturn, which the spacecraft entered orbit in 2004. But on its way to the ringed planet, Cassini passed by Jupiter in December 2000, three years after its launch in October 1997.

The probe's high-resolution cameras caught 26,000 dazzling images of the Jovian atmosphere during its months-long flyby. These photos helped scientists revise their understanding of the red and white bands of gas around the planet.

The Huygens probe dropped to the surface of Saturn's moon Titan in 2005, and the Cassini mothership ended its mission with a suicide plunge into Saturn's atmosphere on Sept. 15, 2017, returning valuable science data to the very end.

New Horizons

The New Horizons spacecraft launched on Jan. 19, 2006, and became the first spacecraft to visit the dwarf planet Pluto in July 2015. New Horizons flew by Jupiter between January and May 2007.

The Jupiter visit was an essential part of New Horizons' mission, as the giant planet's gravity provided a once-in-a-lifetime opportunity to slingshot a craft toward Pluto. During the five-month flyby, New Horizons refined calculations of the orbits of Jupiter's inner moons and took the first spacecraft photos of the planet's Little Red Spot.

Among New Horizons' first pictures were shots of Io, Jupiter's volcanic moon. The spacecraft captured the clearest pictures ever taken of the Tvashtar volcano on Io, showing volcanic fallout that was bigger than the state of Texas.

Current missions

Juno

The Juno mission is only the second spacecraft dedicated to studying the solar system's largest planet. The probe launched on Aug. 5, 2011, and arrived at Jupiter on July 4, 2016.

Now in its extended mission, Juno is the most distant planetary orbiter. Juno is busy studying the planet in detail to give scientists a better idea of the gas giant's weather, magnetic environment and formation history.

Some of the most notable Juno scientific discoveries are the first clear, close-up images of Jupiter's north pole; that the gas giant's magnetic field is far more intense than anyone expected; and the discovery that the cyclone at the center of Jupiter's north pole is surrounded by eight more.

Jupiter Icy Moons Explorer (JUICE)

Artist's illustration shows the JUICE spacecraft in the foreground, the scarred surface of Europa is behind and Jupiter is off to the distance on the right side of the image. — ESA's JUICE probe will take a look at Jupiter's moon Europa. (Image credit: ESA/ATG MediaLab)

The Jupiter Icy Moons Explorer, or JUICE, is an ESA mission to explore Jupiter and three of its icy moons: Europa, Callisto and Ganymede. During the mission, the spacecraft will orbit Ganymede, the solar system's largest moon, and in doing so will become the first probe to orbit a planetary moon other than Earth's.

The mission successfully launched from Europe's Spaceport in Kourou, French Guiana on April 14, 2023. It will take approximately eight years for JUICE to reach the gas giant.

JUICE will join NASA's Europa Clipper, which is due to launch later than JUICE but will arrive in the Jovian neighborhood first.

Approximately four years after it arrives at the Jupiter system, JUICE will proceed to move into orbit around Ganymede to carry out extensive exploration of the giant moon.

Upcoming missions

Europa Clipper

NASA's Europa Clipper mission is set to explore Jupiter's icy moon Europa and determine whether its underground ocean is habitable. The $5 billion spacecraft is due to launch on Oct. 6, 2024.

If the launch goes according to plan, the probe will reach Jupiter on April 11, 2030, where it will enter a long, looping orbit around the gas giant

Europa Clipper, like NASA's Juno mission before it, will adopt an elliptical orbit that takes it far out from Jupiter and the planet's intense radiation for most of the time. Clipper will sail in for a close approach to Europa and then back out, over and over again, for nearly 50 flybys of the ocean moon. This will allow the spacecraft to pass over a different part of Europa each time to survey the entire surface.

Additional information

Read more about the missions that have explored the Jovian neighborhood with these resources from ESA. See the latest Juno news from NASA's official mission page. Keep up to date with the latest Europa Clipper developments with the official mission website.

Bibliography

NASA. (n.d.). Cassini Overview. NASA. Retrieved March 31, 2023, from https://solarsystem.nasa.gov/missions/cassini/overview/

NASA. (n.d.). Juno Overview. NASA. Retrieved March 31, 2023, from https://solarsystem.nasa.gov/missions/juno/overview/

NASA. (n.d.). Pioneer 10 at Jupiter. NASA. Retrieved March 31, 2023, from https://solarsystem.nasa.gov/resources/707/pioneer-10-at-jupiter

NASA. (n.d.). Voyager - Voyager 1, now most distant human-made object in space. NASA. Retrieved March 31, 2023, from https://voyager.jpl.nasa.gov/news/details.php?article_id=2

]]> https://www.space.com/jupiter-missions-brief-history qGVo5867cDhrdZyW7AYES8 Mon, 03 Apr 2023 20:54:49 +0000 Fri, 14 Apr 2023 13:56:56 +0000 <![CDATA[ New Horizons Pluto probe notches 3 new discoveries in outer solar system ]]> NASA's New Horizons probe flew by Pluto nearly eight years ago, but the epic encounter is still bearing scientific fruit.

New Horizons gave humanity its first up-close looks at Pluto on July 14, 2015, when the probe zoomed just 7,800 miles (12,500 kilometers) above the dwarf planet's frigid surface. The mission team is still analyzing the stockpile of data New Horizons gathered during the flyby — and still making intriguing discoveries, as new results show.

New Horizons researchers shared their latest findings on Tuesday (March 14) at the Lunar and Planetary Science Conference (LPSC) being held in Texas and virtually. Among the discoveries presented, one tied Pluto's puzzling flip to its ice-filled basin, another found interesting but puzzling landscapes on the dwarf planet's surface, and a third unveiled the building blocks that formed the snowman-like object Arrokoth, which New Horizons flew by on Jan. 1, 2019.

Pluto's flip tied to Sputnik Planitia

While scientists know that Pluto, like Earth, flipped on its side sometime in its past, Pluto's orientation before the flip and the degree to which it reoriented itself has not been well understood. Scientists who use New Horizons data to study Pluto's geologic past hope to find clues that explain this event.

Now, a group of researchers has attributed Pluto's flip to the formation of Sputnik Planitia, a 620-mile-wide (1,000 km) basin that makes up half of the iconic heart-shaped region on Pluto. Researchers previously knew that Sputnik, which is filled with nitrogen ice, played a profound role in realigning the dwarf planet's surface.

Using images that New Horizons sent home from the 2015 flyby, they are now trying to trace the path of Pluto's flip. In doing so, they found parallel mountain ranges and deep valleys that form what they think is a global tectonic system. These features are more than 186 miles (300 km) wide and span a similar distance from Pluto's north pole.

However, the fact that Pluto changed its orientation in the past reveals that none of the terrains scientists now see is in its original location.

"We can't really explain that in Pluto's current configuration," Oliver White, a New Horizons co-investigator at the SETI (Search for Extraterrestrial Intelligence) Institute in California, said during a presentation Tuesday at LPSC. Instead, these features likely existed along Pluto's equator early on and migrated to their current locations nearer the poles because of the flip, he said.

White's team also found that Pluto's subsurface ocean likely provided some push to Sputnik and helped shift a bulk of the dwarf planet's mass toward its equator.

Related: Why is Pluto not a planet?

The line in red reflects the system of valleys and mountain ranges that scientists think migrated from Pluto's equator to their current positions near its poles. (Image credit: James Tuttle Keane (JPL/Caltech)/NASA/Johns Hopkins APL/SwRI)

Massive knife-like methane ice deposits extend to Pluto's far side

In addition to helping scientists study ancient landscapes on Pluto, New Horizons data is providing clues about its more recent features.

The spacecraft had previously spotted massive methane deposits near Pluto's equator, many as tall as Earth's skyscrapers. Scientists announced Tuesday that they had a new line of evidence suggesting that these knife-like landforms also extend to the far side of Pluto — beyond what New Horizons was able to see during its 2015 flyby.

"The discovery of these features just adds to our understanding of the processes that shape Pluto and other icy planets in our solar system and highlights the complexity, dynamic nature and diversity of planetary surfaces like Pluto's," Ishan Mishra, a postdoctoral researcher at NASA's Jet Propulsion Laboratory in California, said in a statement.

On Earth, such pillars are called penitentes; they are made of water ice and stretch for just a few meters. On Pluto, however, these features primarily exist on the highest points on its surface and soar for hundreds of meters. At such heights, methane freezes out of Pluto's wispy atmosphere in cold weather and evaporates back into its gaseous state during warmer spells.

The team behind the latest study used images snapped by the Long Range Reconnaissance Imager (LORRI) onboard New Horizons, and studied how the light reflected from surfaces changes with different viewing angles.

Doing so, they found similar methane absorption features on the far side of Pluto, thanks to the surfaces being "rougher than average roughness of Pluto," Mishra said during his presentation. Such "bladed" terrains are likely one of the most common landforms on Pluto, he added.

New Horizons scientists are seeing evidence that so-called bladed terrain – a direct response of the landscape to Pluto's changing climate, marked in red on this map – extends across much of the planet. — New Horizons scientists are seeing evidence that so-called bladed terrain — a direct response of the landscape to Pluto's changing climate, marked in red on this map — extends across much of the planet. (Image credit: NASA/Johns Hopkins APL/SwRI)

Piecing together Arrokoth's long-ago merger

On Jan. 1, 2019, New Horizons passed a small object in the Kuiper Belt called Arrokoth, which looks like a partially flattened snowman. Located 4 billion miles (6.6 billion km) from Earth, it became the farthest object ever explored by a spacecraft. It is also the most primitive, thanks to its distance from the sun that keeps in a "deep freeze."

Arrokoth is a gentle fusion of two objects that once orbited each other. The larger of the two lobes, called Wenu, is itself a pile of 12 rocks huddled around a bigger slab, scientists announced on Tuesday. The latest findings show that Wenu formed not as a whole, but by pieces of rock that already existed in the outer reaches of the solar system.

"This is surprising, and a new piece in the puzzle of how planetesimals — building blocks of the planets — like Arrokoth and other Kuiper Belt objects come together," New Horizons principal investigator Alan Stern, from the Southwest Research Institute in Colorado, said in a statement.

Early in the history of the solar system, millions of kilometer-sized icy objects made up a vast, donut-shaped region at its edge called the Kuiper Belt. A few of them amalgamated to form Wenu, Stern said, but these tiny objects did not merge at high speeds, which explains why Wenu is elongated the way it is. (When objects merge at high speeds, their spin throws away material, forming circular bodies.) Since the rocks have retained their shape even after merging, Stern's team estimates that they would have been traveling less than 1 meter per second when they coalesced.

Previous research showed that Wenu tidally interacted with the smaller of the two objects; both lost some angular momentum by ejecting material and eventually merged to form today's Arrokoth.

The individual rocks look like "Lego pieces" and have similar sizes, compositions and colors, all of which tell us "something very important about the formation of Arrokoth," Stern said during his presentation at the conference.

Stern's team found that each of Arrokoth's 12 rocks are more than 3 miles (5 km) wide. Given that Wenu is only 6 miles (10 km) thick, scientists think the 12 rocks clustered around Wenu's equator make up a bulk of its body and also extend to its far side, which wasn't seen by New Horizons.

— NASA celebrates New Horizons' historic 2015 Pluto flyby with awesome new videos

— Solar system planets, order and formation: A guide

Looking inward: A unique view of Uranus and Neptune

Scientists also announced on Tuesday that future New Horizons observations will include clicking color images of both Uranus and Neptune. From its distinct vantage point in the Kuiper Belt, the spacecraft will be well placed for observations that "can only be done by a spacecraft far beyond Uranus and Neptune," said Stern.

Spacecraft within the solar system can only see light reflected from the ice giants inward, or from their sides facing Earth. New Horizons, though, will be able to collect data about the light scattered from the far sides of the planets.

Unlike the test images it clicked in 2019, future observations will be taken as the planets rotate, scientists announced on Tuesday. They say the new images, despite being low resolution that show the two ice giants no clearer than pale blue dots, will help researchers understand more about how cloud structures evolve on the two ice giants.

On June 1, 2022, scientists put New Horizons "to sleep" to save fuel, and the spacecraft woke up from its 10-month hibernation on March 1. From the third week of April, scientists expect the spacecraft to begin studying distant Kuiper Belt objects as well as the two outer gas giants.

The observations about Uranus and Neptune are "going to be very exciting when they do come along," said Will Grundy, a New Horizons co-investigator from Lowell Observatory in Arizona. New Horizons researchers will collaborate with those working with the Hubble Space Telescope, he added.

"The science return is better than either spacecraft can provide on its own," Grundy said in a statement. "It also sets the stage for observations of similar ice giant planets around other stars."

Follow Sharmila Kuthunur on Twitter @Sharmilakg. Follow us on Twitter @Spacedotcom or on Facebook.

]]> https://www.space.com/nasa-new-horizons-pluto-probe-lpsc-2023-discoveries qAHHrUvrPbpcSXaTNDNpM9 Thu, 16 Mar 2023 10:00:21 +0000 Thu, 16 Mar 2023 13:57:33 +0000 <![CDATA[ Queen guitarist and astrophysicist Brian May knighted by King Charles III ]]> Royalty comes in many forms.

For his supreme contributions to the worlds of music and charity, the astrophysicist and Hall of Fame guitar god Brian May was officially knighted on Tuesday (Mar. 14) by King Charles III. May, known for melodious playing with the iconic British rock band Queen, can now formally add "Sir" to his name in recognition for his half-century of memorable musical compositions and inspiring efforts in the arena of animal rights against fox hunting and badger culling.

As part of the official 2023 New Year Honors appointments, which was the first list issued by King Charles III since his ascent to the throne, Brian May received the knighthood title with a touch of the king's ceremonial sword and was awarded the Most Excellent Order of the British Empire.

"This is a kind of license, a kind of commission to carry on doing what I'm doing, and it gives me a bit more power to my elbow," May told BBC News regarding the proud moment. "So I’m very happy about that."

A post shared by Brian Harold May (@brianmayforreal)
A photo posted by on

— Queen's Brian May Outlines Asteroid Deflection Mission

— Astrophysicist Brian May (of Queen!) teaches you how to play the Bohemian Rhapsody solo while in self-isolation

Prior to hooking up to form Queen in 1970 with frontman Freddie Mercury and drummer Roger Taylor, May attended Imperial College London in a post-graduate program studying mathematics and physics. Self-doubt about his aptitudes in that area of learning coupled with the rigors of touring interfering with his studies led to May focusing his goals on a musical career in 1974 where he experienced worldwide acclaim with the famous glam rock group over the decades.

May eventually circled back to his love of astronomy and received his Ph.D. from Imperial College London in 2007. Over the years he's been active in many space-based projects including work on stereoscopic imagery and zodiacal dust, co-founding Asteroid Day, and was attached to NASA's New Horizons Pluto mission in 2015 as part of the science team behind the historic fly-by.

Follow us @Spacedotcom, or on Facebook and Instagram.

]]> https://www.space.com/queen-brian-may-astrophysicist-knighted-king-charles CX9Zc7eG4Cwv3kG8Awckz4 Wed, 15 Mar 2023 21:30:41 +0000 Wed, 30 Apr 2025 17:36:27 +0000 <![CDATA[ Spaceport Cornwall: The ultimate guide to the UK's first spaceport ]]> Spaceport Cornwall is an operational spaceport located in the region of Cornwall, southwest England.

Spaceport Cornwall provides a take-off point for air-launch providers such as Virgin Orbit and potentially a landing site for spaceplanes and does not offer vertical launch services. Work began on Spaceport Cornwall in 2014. In November 2022, it became the first facility in the United Kingdom ever to be granted a spaceport license.

The spaceport is part of Cornwall Airport Newquay, a former Royal Air Force military airport that became a civil airport in 2008. As such, the relatively small airport is home to a large runway that is just over 9,000 ft long and capable of accommodating military aircraft and large passenger airliners.

Melissa Thorpe, head of Spaceport Cornwall, told Space.com in January 2023 that the spaceport expected to employ 150 staff "in direct relation to launch or space" and a total of 240 in the supply chain.

Why was Cornwall selected for a spaceport?

There are several reasons why Newquay Airport Cornwall was selected as a spaceport location, one of which is the aforementioned large runway. Access to the Atlantic Ocean via the nearby Cornish coast and a lack of residential development are also positive factors.

Matthew Archer, Commercial Space Director of the UK Space Agency, told Space.com at the Start Me Up launch in January that even though air launches take place at tens of thousands of feet above the ground, they cannot be carried out in populated areas. "That's why you don't see every airport trying to become a spaceport," he said. "Here, you've got one of the longest runways in the UK at about 10,000 feet — most others aren't that length. So your actual choice, once you move away from military airports, is relatively narrow. That's why Cornwall is such a great location."

LauncherOne model rocket is placed horizontally in a large hangar at spaceport Cornwall. — LauncherOne model rocket at Spaceport Cornwall. (Image credit: Spaceport Cornwall)

The process of building a spaceport within Newquay Airport Cornwall largely involved making use of existing facilities, though two new facilities were constructed: the Space Systems Integration Facility and the Space System Operations Facility. Both will be used by businesses for purposes such as satellite manufacturing and environmental intelligence.

What did it take to establish Spaceport Cornwall?

Melissa Thorpe: Facilities-wise, it didn't take much. We could have launched from day one without really having to do anything. But what we did was future-proof the site and take advantage of the opportunities of launch to create a more sustainable business model by looking at building facilities that can be used by Virgin, but when Virgin are not here can also be used by other businesses as well. So we did things like build our satellite integration facility, which Virgin uses to integrate all the payloads, but in the future we have other people coming in to use it which is great from a revenue generation point of view."

Setting up the spaceport also involved regulatory challenges. The UK's Civil Aviation Authority, the UK's space regulator, granted Spaceport Cornwall its UK spaceport license on November 16, 2022, declaring that the spaceport "met appropriate safety, security, environment and other aspects".

"From a regulatory perspective, it's the first time we've ever launched in the UK," said Thorpe. "We're the first licensed spaceport and we are kind of the guinea pig for that process, so we all were learning as we went along."

Spaceport Cornwall describes its ongoing development cost as just over £20 million ($24.7 million).

Spaceport Cornwall missions

Aerial photograph of Cosmic Girl at Spaceport Cornwall. — Virgin Orbit's Cosmic Girl 747 at Spaceport Cornwall. (Image credit: Virgin Orbit)

The first launch from the facility took place on January 9, 2023, when Virgin Orbit attempted its sixth mission, Start Me Up, which was intended to be the first orbital space launch from the UK. The launch was initially successful but the mission ultimately failed due to Virgin Orbit's LauncherOne rocket ending its second-stage burn prematurely, preventing it from reaching orbit. Archer said the launch project "succeeded in creating a horizontal launch capability at Spaceport Cornwall'' regardless.

Shortly after the mission, Virgin Orbit said in a statement it was anticipating a return to Spaceport Cornwall for additional launches again, possibly before the end of the year.

Other space companies are also expected to use Spaceport Cornwall in the near term. This includes US-based Sierra Space, which is developing a reusable spaceplane capable of carrying crew and cargo to and from low Earth orbit and the International Space Station. "We have a memorandum of understanding with Sierra Space to act as a landing site for their future missions," Thorpe told Space.com. "We have another operator which we haven't announced yet but are hoping to in the next few months."

Missions that launch from Spaceport Cornwall in the near term will likely be with the purpose of deploying small satellites into Earth orbit. As of January 2023, there were no plans for Spaceport Cornwall to launch any space tourism missions. Spaceport Cornwall is expected to host launches twice a year until at least 2028 and is limited to 12 launches per year by the regional branch of government, Cornwall Council.

Facts about Cornwall and its historic space links

Image 1 of 6

Goonhilly Satellite Earth Station in Cornwall, November 13, 1964. (Image credit: Bert Hardy Advertising Archive/Getty Images)

Image 2 of 6

Sign at the entrance to the GPO Goonhilly Satellite Communication Earth Station, with a parabolic antenna in the background, on Goonhilly Downs in southern Cornwall, England, October 1965. (Image credit: Fox Photos/Keystone/Hulton Archive/Getty Images)

Image 3 of 6

Port Isaac, Cornwall, UK (Image credit: Manfred Gottschalk via Getty Images)

Image 4 of 6

View of antennas at the Goonhilly Earth Station (Image credit: Hugh Hastings/Getty Images)

Image 5 of 6

A summer view of the blooming Kidney Vetch and Sea Thrift covered cliffs overlooking Watergate Bay. (Image credit: Photo by Andrew Boxall via Getty Images)

Image 6 of 6

The Cornish Pasty is one of the best-known cuisines from the area. (Image credit: SolStock via Getty Images)

Cornwall has a couple of historic links to space. It was the birthplace of the British mathematician and astronomer John Couch Adams (1819 - 1892), who is known for being one of the astronomers who independently predicted the existence of the planet Neptune, based on observed irregularities in the orbit of Uranus.

It is also home to the Goonhilly Earth Station, a vast radio communications hub used for relaying signals from satellites and the world's first privately-owned deep-space communications network.

Historically the station has been at the forefront of space communications technology. In 1962, Goonhilly's Aerial-1 dish received the first transatlantic TV signal from the earliest communications satellite Telstar. In 1969, the station was used to broadcast the Apollo 11 moon landing to a global audience of around 600 million people.

Goonhilly Earth Station is still in use today and recently tracked the path of NASA's Artemis 1 moon rocket in November 2022 — providing the UK's only tracking support for the mission. It is part of the Spaceport Cornwall consortium.

Outside of space activities, Cornwall is known as one of the six Celtic nations in Europe. It is one of the UK's most popular tourist hotspots owing to its culture, landscape, mild climate, and extensive coastlines. It is also one of the most popular regions in the country for surfing. Culinarily, Cornwall is known for the Cornish pasty and, in a return to the theme of space, stargazy pie — a unique dish that features the heads of whole pilchards protruding upwards from a pastry crust, giving the impression that the fish are looking towards the stars.

Additional resources

To learn more about Spaceport Cornwall's operations visit the spaceport's official website. You can also learn about Cornwall Airport Newquay, where Spaceport Cornwall is based, here. And to find out more about the UK's space operations, visit the official government site of the UK Space Agency.

Bibliography

Spaceport Cornwall receives first-ever UK spaceport licence, CAA.co.uk [Accessed 1/26/23] [https://www.caa.co.uk/news/spaceport-cornwall-receives-first-ever-uk-spaceport-licence/]

EGHQ — Cornwall Newquay, acukwik.com [Accessed 1/26/23] [https://acukwik.com/Airport-Info/EGHQ]

John Couch Adams, NASA.gov [Accessed 1/26/23] [https://starchild.gsfc.nasa.gov/docs/StarChild/whos_who_level2/adams.html]

Virgin Orbit SEC form 8-K, January 12, 2023 [8-K - 01/12/2023 - Virgin Orbit Holdings, Inc.]

Frequently Asked Questions, SpaceportCornwall.com [Accessed 1/26/23] [https://spaceportcornwall.com/faqs/]

Becoming the UK's first Licensed Spaceport: the next step on the Road to Net Zero, SpaceportCornwall.com [Accessed 1/26/23] [https://spaceportcornwall.com/becoming-the-uks-first-licensed-spaceport-the-next-step-on-the-road-to-net-zero/]

]]> https://www.space.com/spaceport-cornwall pdEJFTsZeQx8i3P2ZbF2QA Fri, 03 Feb 2023 13:59:02 +0000 Fri, 03 Feb 2023 13:01:37 +0000 <![CDATA[ The most distant spacecraft in the solar system — Where are they now? ]]> Humans have been flinging things into deep space for 50 years now, since the 1972 launch of Pioneer 10. We now have five spacecraft that have either reached the edges of our solar system or are fast approaching it: Pioneer 10, Pioneer 11, Voyager 1, Voyager 2 and New Horizons.

Most of these probes have defied their expected deaths and are still operating long beyond their original mission plans. These spacecraft were originally planned to explore our neighboring planets, but now they're blazing a trail out of the solar system, providing astronomers with unique vantage points in space — and they've been up to a lot in 2022.

Voyagers 1 and 2

The Voyager missions celebrated a very special anniversary this year: 45 years of operations. From close fly-bys of the outer planets to exploring humans' furthest reach in space, these two spacecraft have contributed immensely to astronomers' understanding of the solar system.

Their main project now is exploring where the sun's influence ends, and other stars' influences begin. Voyager 1 crossed the heliopause, the boundary where the sun's flow of particles ceases to be the most important influence, in 2012 with Voyager 2 following close after, in 2018.

"Voyager 1 has now been in interstellar space for a decade…and it's still going, still going strong," Linda Spilker, Voyager project scientist and a planetary scientist at NASA's Jet Propulsion Laboratory (JPL) in California, told Space.com.

The mission team hit one major hiccup this year, when the spacecraft began sending home garbled information about its location. The engineers found the cause — the spacecraft was using a bad piece of computer hardware when it shouldn't have — and restored operations.

These kinds of incidents are to be expected with an aging spacecraft, though. The team is also actively managing the power supply onboard each spacecraft, which is dwindling each year as the probes' radioactive generators grow increasingly inefficient. This year, mission personnel turned off heaters keeping a number of scientific instruments on board warm in the harsh, cold environment of space — and, much to everyone's surprise, those instruments are still working perfectly well.

orbital diagram showing the five most distant spacecraft. — Humanity's most distant spacecraft and their paths out of the solar system, away from Earth. (Image credit: NASA/Johns Hopkins APL/Southwest Research Institute)

The cameras may have been turned off decades ago, but the spacecrafts' other instruments are collecting data on the plasma and magnetic fields from the sun at a great distance away from the star itself. Because particles of the solar wind — the constant stream of charged particles flowing off the sun — take time to travel such a long way, distant observations allow scientists to see how changes from the sun propagate throughout our cosmic neighborhood.

The edges of the solar system have been full of surprises, too. It would make sense that plasma from the sun becomes more sparse and spread out as you move away from the center of the solar system, but in fact, the Voyagers have encountered much denser plasma after crossing the heliopause. Astronomers are still puzzled about that one.

"It's just so amazing that even after all this time we continue to see the sun's influence in interstellar space," Spilker said. "I'm looking forward to Voyager continuing to operate, perhaps reaching the 50th anniversary."

Pioneers 10 and 11

The Pioneer spacecraft hold a special place in space history because of their role as, you guessed it, pioneers. Unfortunately, these milestone 50-year-old spacecraft are non-functional — Pioneer 10 lost communications back in 2003, and Pioneer 11 has been silent since its last contact in 1995.

But both these spacecraft are marks of humanity's presence in the solar system, and they are still continuing on their journeys, even if we're not sending them commands or firing their rockets anymore. Once a spacecraft is set on a trajectory out of the solar system, according to the laws of physics, it won't stop unless something changes its course.

New Horizons

New Horizons is by far the youngest sibling of these groundbreaking missions, having just launched in 2006. After completing its famous flyby of dwarf planet Pluto in 2015, this probe has been zooming out of the solar system at record speed, set to reach the heliopause around 2040.

Not only has it completed its primary mission, but it successfully completed a flyby of the smaller Kuiper Belt object, Arrokoth, in 2019 as its first mission extension. Earlier this year, the spacecraft was put into hibernation mode because an extended mission hadn't yet been approved. But now, the team is excitedly moving into New Horizons' 2nd Kuiper Belt Extended Mission, or KEM2 for short. KEM2 began on Oct. 1, although the spacecraft will hibernate until March 1, 2023.

In the meantime, the mission team is preparing for exciting new observations. With cutting-edge instruments — far more advanced than what the Voyagers carried in the 1970s — the team is prepared to use New Horizons as a powerhouse observatory in the distant solar system, providing a viewpoint we can't achieve here on Earth.

Bonnie Burrati, planetary scientist at JPL and member of the New Horizons team, is particularly looking forward to new views of Kuiper Belt objects (KBOs), the chunks of ice and rock beyond Neptune. New Horizons' unique position in the outer solar system provides new angles of looking at these KBOs, she said. Different views can tell astronomers about how rough the objects' surfaces are, among other things, based on how light scatters and creates shadows on them.

Another planetary scientist on the team from Southwest Research Institute in Colorado, Leslie Young, wants to use the spacecraft for a new look at something closer to home: the ice giants, Uranus and Neptune. New Horizons’ unique viewpoint provides scientists with information about how light scatters through the planets’ atmospheres—information we can’t get from here on Earth, since we can’t see Uranus and Neptune from that angle. Planetary scientists are eager for more information about these planets, especially as NASA begins planning for a new mission to visit Uranus.

When the spacecraft wakes from hibernation, it will be past the so-called "Kuiper cliff," where scientists currently think there are far fewer large KBOs. "When we look at other star systems, we see debris disks extending to much larger distances from their host stars," Bryan Holler, an astronomer at Baltimore's Space Telescope Science Institute, told Space.com. "If ET were to look at our solar system, would they see the same thing?"

This next extended mission will even venture beyond New Horizons' original domain of planetary science. Now, the spacecraft will provide better-than-ever measurements of the background of light and cosmic rays in space, trace the distributions of dust throughout our solar system, and obtain crucial information on the sun's influence, complimentary to the Voyagers. Since the three functional far out spacecraft are heading in separate directions, they allow astronomers to map out irregularities in the solar system's structure.

Luckily for New Horizons, signs indicate that the spacecraft will have enough power to last through the 2040s and possibly beyond — each year, moving 300 million miles (480 million kilometers) farther into uncharted territory.

Follow the author at @briles_34 on Twitter. Follow us on Twitter @Spacedotcom and on Facebook.

]]> https://www.space.com/most-distant-spacecraft-voyagers-new-horizons NspG2RWzxzaZbc6pTpErfW Fri, 30 Dec 2022 11:00:30 +0000 Thu, 22 Dec 2022 21:09:29 +0000 <![CDATA[ Far beyond Pluto: What's next for NASA's New Horizons probe? ]]> NASA's New Horizons spacecraft flew by Pluto seven years ago, but the probe's work is far from done.

New Horizons is still on duty in extended mission mode, diving ever deeper into the Kuiper Belt to examine ancient, icy mini-worlds in that vast region beyond the orbit of Neptune.

New Horizons launched in January 2006 and carried out a reconnaissance study of Pluto and its moons in the summer of 2015, culminating in a close flyby of the dwarf planet on July 14, 2015. That encounter revealed Pluto to be an incredibly diverse world, complete with towering water-ice mountains and huge plains of exotic nitrogen ice.

But the nuclear-powered probe kept its eyes open even after Pluto was in the rear-view mirror.

Destination Pluto: NASA's New Horizons mission in pictures

Primitive object

New Horizons next flew by Arrokoth, a small Kuiper Belt object (KBO), on Jan. 1, 2019. Arrokoth, which the New Horizons science team discovered in 2014 using the Hubble Space Telescope, is the most distant and most primitive object ever explored up close by a spacecraft.

And there could be another flyby in New Horizons' future as well.

At a meeting of NASA's Outer Planets Assessment Group (OPAG) in June, New Horizons principal investigator Alan Stern, of the Southwest Research Institute (SwRI) in Colorado, related that both the spacecraft and its scientific payload are entirely healthy. The probe's lifetime is presently limited only by its nuclear fuel supply, which is likely sufficient to keep New Horizons flying through 2040.

And NASA recently granted another mission extension for New Horizons, which will keep the spacecraft going through 2025.

"I am very excited about this second extended mission," Stern told Space.com. NASA and the New Horizons team are discussing budget numbers for fiscal year 2025, he added.

Main action items

Now on the New Horizons agenda are a trio of main action items, as approved by NASA. One involves looking for another flyby target "and also more KBOs that we can study, not up close, but in the distance," Stern said.

In addition, New Horizons is still transmitting the last bytes of data gathered during the Arrokoth flyby in 2019.

"We got delayed in that, mostly because the Deep Space Network had some upgrades. They took antennas down, and one was down for a year," Stern said. "We've got roughly 90% of the Arrokoth flyby [data] on the ground, but we want everything, and that takes time. So that's a significant activity."

Then there's the centerpiece of New Horizons' second extended mission — a diversity of observations across a variety of fields.

"While we are flying across the Kuiper Belt," added Stern, "we are going to be doing a very interdisciplinary mission in all the space sciences — astrophysics, planetary science and heliophysics. We're going to use this spacecraft to do things that really cannot be done except if you have a spacecraft out there. There's really never been anything like this … We're doing all three different space sciences by making New Horizons an observatory for all three purposes."

For example, in heliophysics, the spacecraft will study "pickup ions." These charged particles dominate the pressure of the outer heliosphere — the huge bubble of magnetic fields and particles that the sun blows around itself — and control where the boundary with the interstellar medium is situated.

In astrophysics, New Horizons will study the cosmic optical and ultraviolet background, getting a nice view beyond the obscuring dust and other scattered light sources of the solar system's inner regions. New Horizons has already produced the most sensitive measurements of these backgrounds to date, with "deep implications for cosmology," Stern noted.

In the planetary science column, the probe is slated to study Uranus and Neptune from unique "high phase angle" geometries, shedding light on the important energy balances of those planets.

"There's never been anything really deeply interdisciplinary like New Horizons is going to become for this next three years in extended mission," said Stern.

Machine learning

The New Horizons team also plans to obtain time on ground-based telescopes such as Keck and Subaru to find new KBOs to study as the probe zips by them, "or if you get lucky and pass one that's close enough we could get to, we'll have a close flyby," Stern said.

The New Horizons team is employing machine learning to hunt for new KBOs using such scopes. "It turns out it is faster, more accurate, more reliable," said Stern. Weighed against human sleuthing, machine learning "is better and finds more KBOs. So that's a breakthrough and saves us a lot of work and turns out a better product."

Ground-based observations have shown that there are different classes of KBOs that have different colors and compositions. "So we know there's a lot of heterogeneity among the KBOs," Stern said. "If we had a flyby of a second KBO, I would not expect the same thing at all. It would be a completely different place than Arrokoth."

Building blocks

KBOs teach scientists about planetesimals, the building blocks of planets thought to exist in protoplanetary disks and debris disks.

The Arrokoth KBO flyby yielded a breakthrough result, Stern said: That at least some planetesimals formed very gently, in a process called a local cloud-collapse phenomenon. The New Horizons team would love to study another KBO up close, to see if its formation and evolution match what was observed at Arrokoth.

"We're turning this into a machine that does good for astrophysics and heliophysics while it's doing good for planetary science," Stern said about New Horizons and its second extended mission. "They are equal partners in science, and that is a first for a planetary science mission."

Leonard David is author of the book "Moon Rush: The New Space Race," published by National Geographic in May 2019. A longtime writer for Space.com, David has been reporting on the space industry for more than five decades. Follow us on Twitter @Spacedotcom or on Facebook.

]]> https://www.space.com/beyond-pluto-nasa-new-horizons-next-steps ZGVhxCKv62pn2LeCDmKC7n Thu, 14 Jul 2022 10:00:18 +0000 Tue, 26 Jul 2022 12:20:28 +0000 <![CDATA[ These 8 NASA missions just got more time to explore Mars, asteroids and the solar system ]]> Eight interplanetary spacecraft have a go to continue their missions at Mars, the moon or various asteroids.

NASA extended these the work of these missions "due to their scientific productivity and potential to deepen our knowledge and understanding of the solar system and beyond," the agency said in a statement.

The decision to keep these longstanding missions going happened after independent reviews of their work, including academia, industry and NASA input. The panel evaluations comprising 50 reviewers "validated that these eight science missions hold substantial potential to continue bringing new discoveries and addressing compelling new science questions," the agency said.

Here's a brief look at the extended missions and what they will do next.

1) Curiosity rover on Mars

NASA's Curiosity rover imaged Mars using its navigation cameras. (Image credit: NASA/JPL-Caltech)

Curiosity, also known as the Mars Science Laboratory (MSL), landed on Mars in 2012 and will explore for another three years. It has spent several years climbing Mount Sharp (Aeolis Mons) after landing on the Red Planet's Gale Crater. It is on a long-term hunt to understand how water, and potential conditions for life, arose in that region of the planet.

"In its fourth extended mission, MSL will climb to higher elevations, exploring the critical sulfate-bearing layers which give unique insights into the history of water on Mars," NASA stated.

2) Lunar Reconnaissance Orbiter at the moon

NASA's Lunar Reconnaissance Orbiter photographed the Apollo 11 lunar module and the rest of the mission's landing site in 2009. (Image credit: NASA/GSFC/Arizona State University)

The Lunar Reconnaissance Orbiter (LRO) has been in operation since 2009, and will work for another three years. It is best-known for mapping surface detail of the moon in high-definition, tracking down landing missions (or crashes) past and present, and seeking preserves of ice water on the moon.

NASA will be using its data in planning for its Artemis moon-landing program that plans boots on the surface no earlier than 2025, the agency said, giving LRO another three years for this work.

"LRO will continue to study the surface and geology of the moon," NASA stated of the extension. "The evolution of LRO's orbit will allow it to study new regions away from the poles in unprecedented detail, including the permanently shadowed craters near the poles where water ice may be found. LRO will also provide important programmatic support for NASA's efforts to return to the moon."

3) OSIRIS-APEX/OSIRIS-REx at asteroid Apophis

NASA's OSIRIS-REx spacecraft captured this image of the asteroid Bennu using its MapCam imager on Dec. 12, 2018. (Image credit: NASA/Goddard/University of Arizona)

The Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) mission will have another stop after dropping off pieces of asteroid Bennu at Earth in 2023. The spacecraft, in flight since 2016, will be redirected to visit Apophis, a near-Earth asteroid that was once deemed a slight threat to Earth in 2068. The mission will also acquire a new name: OSIRIS-Apophis Explorer (APEX).

The renamed mission will orbit Apophis shortly after the asteroid safely comes within 20,000 miles (32,000 kilometers) of Earth in 2029, NASA stated. "It plans to study changes in the asteroid caused by its close flyby of Earth, and use the spacecraft’s gas thrusters to attempt to dislodge and study the dust and small rocks on and below Apophis’ surface."

OSIRIS-APEX will have a new principal investigator: Daniella DellaGiustina, a planetary scientist at the University of Arizona who is deputy principal investigator on the current mission, OSIRIS-REx. The principal investigator for OSIRIS-REx, planetary scientist Dante Lauretta from the same university, will pivot to analyzing samples from Bennu after their return.

4) MAVEN at Mars

An artist's depiction of NASA's MAVEN spacecraft in orbit around Mars. (Image credit: NASA/GSSFC)

The Mars Atmosphere and Volatile EvolutioN mission (MAVEN) launched in November 2013 to look at changes in the atmosphere of the Red Planet. It is suspected that gradual erosion of the atmosphere over the eons led to less running water at the surface of Mars, when pressure dropped.

The extended mission, which will clock another three years, "plans to study the interaction between Mars' atmosphere and magnetic field during the upcoming solar maximum," NASA stated. "MAVEN's observations as the sun's activity level increases toward the maximum of its 11-year cycle will deepen our understanding of how Mars' upper atmosphere and magnetic field interact with the sun."

MAVEN will also acquire a new principal investigator: Shannon Curry, a planetary scientist at the University of California, Berkeley. (The previous one, Bruce Jakosky from the Laboratory for Atmospheric and Space Physics at the University of Colorado Boulder, announced his departure in September 2021.)

5) InSight Mars lander

NASA's InSight lander snapped this image of the area in front of it on July 20, 2021. (Image credit: NASA/JPL-Caltech)

InSight landed on Mars in 2018 and has been useful in getting information on "marsquakes" to learn more about the planet's interior and how that evolved over the eons.

The spacecraft has been working well, aside from the failure of a below-surface probe known as a "mole" and gradual dust buildup on its solar panels. Given its shaky power status, the mission has a few more months tacked on its mission until the end of 2022, but may not last that long.

"The extended mission will continue InSight's seismic and weather monitoring if the spacecraft remains healthy," NASA stated. "However, due to dust accumulation on its solar panels, InSight's electrical power production is low, and the mission is unlikely to continue operations for the duration of its current extended mission unless its solar panels are cleared by a passing 'dust devil' in Mars’ atmosphere."

6) New Horizons in the Kuiper Belt

New Horizons launched in 2006 and has visited two worlds so far: dwarf planet Pluto in 2015, and the Kuiper Belt object Arrokoth (2014 MU69) in 2019. The mission is expected to fly as far as 63 astronomical units (or Earth-sun distances) in its next three years, but what is coming next (and if another flyby is planned) is still under wraps.

"The New Horizons spacecraft can potentially conduct multi-disciplinary observations of relevance to the solar system, and NASA's heliophysics and astrophysics divisions. Additional details regarding New Horizons' science plan will be provided at a later date," NASA stated.

7) Mars Odyssey

This stunning view shows what an explorer might see on the Red Planet's north pole. This image is a 3D view created from observations recorded by the THEMIS instrument on NASA's Mars Odyssey spacecraft. Image released May 26, 2016. (Image credit: NASA/JPL/Arizona State University, R. Luk)

The Mars Odyssey spacecraft started work in 2001 and continues to work well in its third decade in space. While NASA warned the mission is running low on propellant, it hopes to squeeze another three years from the mission. Besides being a remote scientist, Odyssey serves as a relay for other Mars spacecraft on the surface in sending their communications back to Earth.

On the science side, NASA stated, "Mars Odyssey's extended mission will perform new thermal studies of rocks and ice below Mars’ surface, monitor the radiation environment, and continue its long-running climate monitoring campaign."

8) Mars Reconnaissance Orbiter

A new crater on Mars, which appeared sometime between September 2016 and February 2019, shows up as a dark smudge on the landscape in this high-resolution photo from the Mars Reconnaissance Orbiter. (Image credit: NASA/JPL/University of Arizona)

The Mars Reconnaissance Orbiter has been in service since 2005 and provides a long-term view of the surface of the Red Planet. It charts changes in sand dunes, ice caps and other features and also keeps an eye on missions on the Red Planet.

Aside from the loss of one instrument (the Compact Reconnaissance Imaging Spectrometer for Mars, or CRISM) due to a loss of coolant that shut down one of the two spectrometers, the mission should operate for another three years. MRO will continue its relay services for surface missions, too.

"In its sixth extended mission, MRO will study the evolution of Mars’ surface, ices, active geology, and atmosphere and climate. In addition, MRO will continue to provide important data relay service to other Mars missions," NASA stated.

Follow Elizabeth Howell on Twitter @howellspace. Follow us on Twitter @Spacedotcom or Facebook.

]]> https://www.space.com/nasa-extends-8-solar-system-missions-mars-asteroids bYkYKEG2RFA9FyxJYNPuL8 Tue, 26 Apr 2022 18:42:14 +0000 Thu, 28 Apr 2022 14:12:01 +0000 <![CDATA[ Ice volcanoes on Pluto may still be erupting ]]> An area of Pluto that researchers think was formed from the eruption of ice volcanoes is unique on the dwarf planet and in the solar system, a new study suggests.

NASA's New Horizons mission, which launched in 2006, took detailed photos of the surface of Pluto, a dwarf planet and the largest object in the Kuiper Belt. Now, a new analysis examines images of an area containing two main mounds that scientists have proposed are ice volcanoes. In the study, the researchers conclude that the surface around these mounds was likely formed by fairly recent activity of the ice volcanoes, or cryovolcanoes.

The finding raises the possibility that these volcanoes may still be active and that liquid water, or something like it, flows or recently flowed under the surface of Pluto. Recent activity also means that there is likely more heat in Pluto's interior than scientists previously thought. Given other recent research, the scientists say their work could even raise the possibility of life existing under Pluto's surface.

The researchers analyzed photographs of a region dominated by two large mounds, called Wright Mons and Piccard Mons, which scientists think are cryovolcanoes. Wright Mons is a mount 2.5 to 3 miles (4 to 5 kilometers) high and about 90 miles (150 km) wide, while Piccard Mons is about 4 miles (7 km) high and 150 miles (250 km) wide.

The suspected ice volcanoes also have extremely deep depressions at their peaks — the one on Wright Mons is about as deep as the mount is high. Many parts of the area also have an unusual, lumpy or "hummocky" appearance, made up of undulating, rounded mounds. The researchers think smaller mounds, formed from ice volcanoes, could have accumulated over time to form these two main mounds.

"There was no other areas on Pluto that look like this region," Kelsi Singer, a planetary scientist at the Southwest Research Institute in Boulder, Colorado and the lead author of the study, told Space.com. "And it's totally unique in the solar system."

Unlike other areas of Pluto, this area has few to no impact craters, indicating that the surface was formed relatively recently in geological time. Based on the lack of craters, the area is likely no older than one or two billion years old, with some areas likely being less than 200 million years old, Singer said.

A view of an icy volcanic region on Pluto. (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Isaac Herrera/Kelsi Singer)

In some ways, cryovolcanoes are analogous to volcanoes on Earth, since much of Pluto's surface is made of ice, and temperatures on Pluto are far below water's freezing point. That means that liquid water, or something like it which is at least partially fluid or mobile, would be like magma on Earth, coming up to the surface after an eruption and freezing, or hardening, into a solid.

"It's probably not coming up completely liquid — it's probably more like a slushy thing where you have some liquid and some ice, or it could even be more like a flowing solid," Singer said, which could be "more like ketchup or silly putty." It could even be more solid ice that can still flow.

"We all know that ice can flow because we have glaciers that flow on Earth," she said.

Though scientists don't totally understand how cryovolcanic activity on Pluto might work, it is likely powered by radiogenic heat created by the decay of radioactive elements in the dwarf planet's interior. A similar phenomenon is also one of the sources of heat in the Earth's interior, although Pluto does not have plate tectonics, the complex system of shifting continental crust that underlies geologic activity on Earth. Scientists call geologic activity like that on Pluto "general tectonics," which can still create features like faults in rock but does not have tectonic plates.

Pluto's cryovolcanoes display some similarities to shield volcanoes on Earth, which are low-profile volcanoes which form from the steady accumulation of lava flows into rounded structures. (Think of the Hawaiian island volcanoes, rather than an eruption like Mount St. Helens or Vesuvius.) But shield volcanoes usually form from very liquid lava, unlike what scientists think happened on Pluto.

Some volcanoes on Earth and other planets also have a depression in their middle called a caldera, formed when a newly erupted volcano collapses into the void left by all the material it spewed out. But the depression on Wright Mons is so deep that the volcano would have had to lose about half of its volume to be similar in shape to Mauna Loa, a shield volcano in Hawaii that is one of the largest volcanoes on Earth and has a comparatively small caldera, though the two structures are similar in volume, Singer said.

There's still a lot researchers don't know about these features, how they were formed, and how cryovolcanism works on Pluto. The idea that liquid water could exist beneath the surface of Pluto raises the chances of life existing on Pluto from practically non-existent to slightly more plausible, given other research suggesting that Pluto was hot when it first formed and could still have a liquid ocean under its icy surface.

"I think that it is a little more promising, and that there might be some heat and liquid, potentially liquid water closer to the surface," Singer said. "But there's still some big challenges for poor microbes that want to live on Pluto."

The research is described in a paper published Tuesday (March 29) in the journal Nature Communications.

Follow us on Twitter @Spacedotcom and on Facebook.

]]> https://www.space.com/pluto-recent-ice-volcanoes-new-horizons EptPrimD4qq8BamA4vphkZ Tue, 29 Mar 2022 16:00:40 +0000 Fri, 01 Apr 2022 19:11:29 +0000 <![CDATA[ The icy 'space snowman' Arrokoth in deep space just got names for its best features ]]> The map of a distant, lobe-shaped object called Arrokoth (2014 MU69) now has official names to accompany the images from NASA's New Horizons spacecraft.

After the spacecraft zoomed by the lobe-shaped world in 2019, managers of the mission — most famous for its flyby of Pluto four years before — announced the proposed feature names were approved by the International Astronomical Union.

The names closely follow the theme of the name "Arrokoth," which means "sky" in the Powhatan/Algonquin Native American language. (Algonquin territory also includes parts of Canada, where such populations are usually called "Indigenous" or "First Nations.")

"Naming these features on Arrokoth is a milestone that the New Horizons team is very proud to reach," Alan Stern, the New Horizons mission's principal investigator at the Southwest Research Institute in Colorado, said in a statement from Johns Hopkins University Applied Research Laboratory, which built and operates the spacecraft.

"It's a significant step in our discovery and exploration of this ancient object," Stern added of the naming, "in a distant region of the solar system we're just beginning to learn about."

Destination Pluto: NASA's New Horizons mission in pictures

The names focus on three prominent features on the the 22-mile (35-kilometer) long world: a near-circular arc on the larger lobe of Arrokoth, the "neck" or joining area between the lobes, and a large crater located on the smaller lobe.

The arc will be named "Ka'an," the word for "sky" in the Yucatec Mayan language spoken in parts of the Mexican Yucatan Peninsula and Belize. "It also resembles the word for 'snake' in this language — 'kan' — and both terms derive from the classical Mayan word, 'chan,'" JHUAPL stated. (Snakes were often associated in Mayan paintings with the sky, or heaven.)

The three prominent features on the Kuiper Belt object Arrokoth — explored by NASA's New Horizons spacecraft in January 2019 — now have official names. (Image credit: NASA/Johns Hopkins APL/Southwest Research Institute)

The neck is named "Akasa," the word for sky in Bengali (Bangla), and derived from similar words in Sanskrit (ākāśam), Nepali (akās), Malayalam (ākāśaṃ), Oriya (akaśô), Sinhalese (ākāśaya), Tamil (ākāyam) and Telugu (ākāśamu).

Lastly, the large crater is named "Sky," in English. (During the flyby, the nickname for this crater was "Maryland," where JHUAPL is located.)

New Horizons remains in excellent health, and the team is scanning the region for a longshot third flyby that may take place in the 2030s. The challenge in planning such a flyby, Stern said in a mission update in 2021, is that the Kuiper Belt is so thinly populated that objects are hard to find.

Follow Elizabeth Howell on Twitter @howellspace. Follow us on Twitter @Spacedotcom and on Facebook.

]]> https://www.space.com/arrokoth-feature-names-new-horizons XJN4qPNhjShXZToKw9sPaH Thu, 03 Mar 2022 17:00:34 +0000 Mon, 07 Mar 2022 14:40:39 +0000 <![CDATA[ Pluto's bizarre polygons now have a science explanation ]]>

Pluto composite

A composite image of Pluto created using data from NASA's New Horizons mission. (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

Pluto is geologically alive.

Bizarre geometric shapes first spotted on the dwarf planet's surface in 2015 are indications that a process called sublimation is ongoing, a new study suggests.

A fresh model indicates that the polygonal nitrogen ice on Pluto — spotted by NASA's New Horizons spacecraft during a flyby — froze directly from vapor, rather than passing through a liquid state in between.

Lead author Adrien Morison, a research fellow at the University of Exeter in England, said his team's work is the first explanation, based on modeling, that shows why the polygons are there.

"Pluto is still geologically active despite being far away from the sun and having limited internal energy sources," Morison said in a university statement. "This included at Sputnik Planitia, where the surface conditions allow the gaseous nitrogen in its atmosphere to coexist with solid nitrogen."

The surface of Pluto’s icy Sputnik Planum — seen here in a photo captured by NASA’s New Horizons spacecraft during its close flyby of the dwarf planet on July 14, 2015 — is covered with churning ice “cells” that are geologically young and turning over due to convection. — The surface of Pluto's icy Sputnik Planum — seen here in a photo captured by NASA’s New Horizons spacecraft during its close flyby of the dwarf planet on July 14, 2015 — is covered with churning ice “cells” that are geologically young and turning over due to convection. (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

Sputnik Planitia is the most prominent geological feature on Pluto, as it is a huge oval-shaped zone straddling the equator of Pluto. Estimates from 2016, when it used to be called Sputnik Planum, peg the zone at 347,500 square miles (900,000 square kilometers) and at least 1.2 to 1.8 miles (2 to 3 km) deep.

The new study consisted of numerical simulations, showing that as the nitrogen at Pluto cools during sublimation in Sputnik Planitia, it will produce polygons consistent with the size and topographical amplitude seen in New Horizons' images. The new model also is consistent with larger worldwide climate models showing that the sublimation of Sputnik Planitia started one million or two million years ago.

This sublimation process may occur at other icy worlds around the solar system, the team noted, including Triton (a large moon at Neptune), or the Kuiper Belt objects Eris and Makemake far out in the solar system. But more observations of their surfaces would likely be required, which would in turn likely need spacecraft. Thus far there are no missions slotted to visit these various worlds.

A study based on the research was published Wednesday (Dec. 15) in Nature.

Follow Elizabeth Howell on Twitter @howellspace. Follow us on Twitter @Spacedotcom or Facebook.

]]> https://www.space.com/pluto-bizarre-polygon-science Ug4Ju3Yq6u5rVXS5HrM73T Fri, 17 Dec 2021 11:58:06 +0000 Fri, 17 Dec 2021 11:58:06 +0000 <![CDATA[ Water's ultimate freezing point just got lower ]]> "Ice cold" just got even colder: By creating ice from tiny droplets only a few hundred molecules in size, researchers have pushed water's freezing point lower than ever before and changed what we know about how ice forms.

Knowing how and why water transforms into ice is essential for understanding a wide range of natural processes. Climate fluctuations, cloud dynamics and the water cycle are all influenced by water-ice transformations, as are animals that live in freezing conditions.

Wood frogs, for example, survive the winter on land by allowing their bodies to freeze. This allows them to come out of hibernation faster than species that spend the winter deep underwater without freezing. But ice crystals can rupture cell membranes, so animals that use this technique need to find a way to prevent ice from forming in their cells and tissues. A better understanding of how water freezes could lead to a better understanding of these extreme species.

While the rule of thumb is that water freezes at 32 degrees Fahrenheit (0 degrees Celsius), water can actually stay liquid over a range of chilly temperatures under certain conditions. Until now, it was believed that this range stopped at minus 36 degrees F (minus 38 degrees C); any lower than that, and water must freeze. But in a study published Nov. 30 in the journal Nature Communications, researchers managed to keep droplets of water in a liquid state at temperatures as low as minus 47.2 degrees F (minus 44 degrees C).

There were two keys to their breakthrough: very small droplets and a very soft surface. They began with droplets ranging from 150 nanometers, barely bigger than an influenza virus particle, to as small as 2 nanometers, a cluster of only 275 water molecules. This range of droplet sizes helped the researchers uncover the role of size in the transformation from water to ice.

"We covered all of these ranges so that we can understand at which condition ice is going to form — which temperature, which size of the droplets," study co-author Hadi Ghasemi, a mechanical engineering professor at the University of Houston, told Live Science. "And more importantly, we found that if the water droplets are covered with some soft materials, the freezing temperature can be suppressed to a really low temperature."

The soft material they used was octane, an oil that surrounded each droplet within the nanoscale pores of an anodized aluminum oxide membrane. That allowed the droplets to take on a more rounded shape with greater pressure, which the researchers say is essential for preventing ice formation at these low temperatures.

Because it's basically impossible to observe the freezing process at these small scales, the researchers used measures of electrical conductance — since ice is more conductive than water — and light emitted in the infrared spectrum to catch the exact moment and temperature at which the droplets transformed from water to ice.

They found that the smaller the droplet, the colder it had to be for ice to form — and for droplets that were 10 nanometers and smaller, the rate of ice formation dropped dramatically. In the smallest droplets they measured, ice didn't form until the water had reached a bone-chilling minus 44 degrees C.

Does this mean that the microscopic droplets within clouds and biological cells can get even colder than we thought? "As a scientist, I would say we don't know yet," Ghasemi said.

But this discovery could mean big things for ice prevention on human-made materials, like those in aviation and energy systems, Ghasemi said. If water on soft surfaces takes longer to freeze, engineers could incorporate a mix of soft and hard materials into their designs to keep ice from building up on those surfaces.

"There are so many ways that you can use this knowledge to design the surfaces to avoid ice formation," Ghasemi said. "Once we have this fundamental understanding, that next step is just the engineering of these surfaces based on the soft materials."

Originally published on Live Science.

]]> https://www.space.com/water-lower-freezing-point hKDgdCmQZJtFsPnF25AGmn Thu, 16 Dec 2021 11:00:40 +0000 Thu, 16 Dec 2021 01:30:46 +0000 <![CDATA[ New Horizons: Exploring Pluto and Beyond ]]> NASA's New Horizons became the first spacecraft to visit dwarf planet Pluto in July 2015. The far-traveling spacecraft also visited a distant Kuiper Belt object Ultima Thule (2014 MU69) – now called Arrokoth – in January 2019. New Horizons is still exploring our solar system and on April 17, 2021, the spacecraft reached a distance of 50 astronomical units (AU) from the sun. (One AU is the average Earth-sun distance — about 93 million miles, or 150 million kilometers.)

Observations from New Horizons are continuing to revolutionize our understanding of solar system objects orbiting far from the sun. The spacecraft's extreme distance from Earth makes it only the fifth to venture so far from home, the others being Pioneer 10 and Pioneer 11, and Voyager 1 and Voyager 2. So far, only Voyager 1 and Voyager 2 have voyaged so far that they entered interstellar space. According to NASA, New Horizons is expected to enter interstellar space in the 2040s.

New Horizons is the first of NASA's New Frontiers mission probes, which are medium-class missions designed to explore different destinations in the solar system. (Other selected missions include the Juno Jupiter mission and the OSIRIS-ReX mission to return a sample from asteroid Bennu.)

New Horizons was initially selected for funding in 2001 but was excluded from the NASA 2003 budget. Funding for the mission was reinstated after New Horizons was listed as a top priority in the Planetary Science Decadal Survey of 2003–2013, which identifies scientific targets for future exploration.

Spacecraft typically have a set design lifetime, similar to warranties on electronics or cars. Over time, solar particles, cosmic rays and other phenomena can degrade the surface of the spacecraft or mess up the electronics. This makes long missions like New Horizons especially challenging, requiring backup systems and a source of power (nuclear power) to keep the spacecraft alive far away from the sun.

New Horizons was launched Jan. 19, 2006, on an Atlas V rocket from Cape Canaveral Air Force Station in Florida. A power outage and high winds had delayed two previous launch attempts, but New Horizons made it safely into space on the third try.

New Horizons Jupiter flyby

montage New Horizons images of Jupiter and Io — This is a montage of New Horizons images of Jupiter and its volcanic moon Io, taken during the spacecraft’s Jupiter flyby . The image was released in Oct. 2007. (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Goddard Space Flight Center)

New Horizons' first target was Jupiter, which it visited in February and March 2007. The spacecraft passed by at less than 1.4 million miles (2.4 million kilometers) from the solar system's largest planet, making this the first spacecraft to swing by since the Galileo probe finished its mission at Jupiter in 2003.

Additionally, the spacecraft flew through a stream of charged particles swirling behind Jupiter. The probe found large bubbles of charged particles, or plasma, and also revealed variations in the stream of particles. At the time, astronomers said the observations could help with understanding the environment around "hot Jupiter" planets found at other stars, or planets the size of Jupiter that orbit very close (the equivalent orbit of Mercury, or even closer) to their stars.

To conserve energy and lessen the chance of anything breaking, controllers kept the Pluto-traveling spacecraft in hibernation, aside from periodic wake-ups for navigation and systems checks. NASA had the probe emerge from hibernation in December 2014, so it could get ready for the Pluto encounter and send data back to Earth.

New Horizons reaches Pluto

high-resolution image of Pluto as New Horizons bids the dwarf planet farewell — New Horizons captured this image of Pluto's receding crescent when as it bid farewell to the dwarf planet. The image was captured when New Horizons was 120,000 miles (200,000 kilometers) away from Pluto. (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

New Horizons was so busy gathering data in its July 2015 encounter that, as planned, the spacecraft didn't communicate with Earth during its closest approach to Pluto and the dwarf planet's largest moon, Charon. Controllers celebrated when New Horizons phoned home, as they knew that data was on the way.

Pluto's distance, about 3 billion miles (5 billion km) from Earth, presented power challenges for the New Horizons designers since the sun's rays at that distance are too weak to generate power. There are also long communications delays for those staying in touch with the 1,054-lb. (478 kilograms) spacecraft. When New Horizons reached Pluto, it took 4.5 hours for a one-way message to get there from Earth.

According to NASA, it took 15 months to download the entire dataset collected during Horizons’ encounter with Pluto and Charon. This was because New Horizons could only transmit about 1-2 kilobits of data per second and there were about 6.25 gigabytes in total. It was undoubtedly worth the wait.

Early pictures from New Horizons showed a surprisingly young surface on Pluto, with a mountain range as high as 11,000 feet (3,500 meters). Believed to be about 100 million years old at most, this range likely points to recent geological activity on the surface, but it's unclear what caused it.

"This may cause us to rethink what powers geological activity on many other icy worlds," said John Spencer, New Horizons geology, geophysics and imaging team deputy leader, in a statement released shortly after the encounter.

Halo-like craters on Pluto's surface display a puzzling distribution of methane ice and water ice. (Image credit: NASA/JHUAPL/SwRI)

More youthful terrain — such as a huge plain bereft of craters, just north of the mountainous range — popped up in pictures sent back in mid-July of 2015. The zone has been informally named Sputnik Planitia and is a region of intense scrutiny, given that geologists are still trying to figure out what caused it.

Other telescopes found several new moons at Pluto during New Horizons' journey to the dwarf planet, presenting a challenge for spacecraft navigators, who were concerned about orbital debris affecting the spacecraft’s trajectory. Fortunately, the moons were found well ahead of the Pluto encounter, and New Horizons faced no obstacles while whizzing through Pluto's system.

Some of New Horizons' other scientific discoveries included evidence of a past subsurface ocean on Charon and strange water-ice hills on Pluto floating in frozen nitrogen. In 2018, one study suggested that there may be an asphalt layer on Pluto, just beneath the world's surface. Some scientists have also suggested that Pluto could have the ingredients for life on its surface, even at its great distance from the sun.

Pluto's Sputnik glacier — This high-resolution image from New Horizons shows the “shoreline” of Sputnik Planitia on Pluto. (Image credit: NASA/JHUAPL/SwRI)

Pluto's planetary status change

New Horizons was already in space when the International Astronomical Union voted to change Pluto's status to "dwarf planet" in 2006, following the discovery of several similar-size objects in the Kuiper Belt.

New Horizons principal investigator Alan Stern has repeatedly said he is not in favor of the decision, especially after the flyby revealed that Pluto has a more complex formation history than initially anticipated.

In 2017, a group of planetary scientists submitted a proposal to reclassify Pluto as a planet, making their recommendations at the 48th Lunar and Planetary Science Conference in The Woodlands, Texas. The proposal redefined a "planet" as a round object that has never experienced fusion (unlike a star); the definition is expected to encompass not only dwarf planets, but also moons. Officially, Pluto is still considered a dwarf planet as of late 2021.

Arrokoth (2014 MU69) flyby

Composite image Arrokoth — Composite image of Arrokoth obtained from data collected by New Horizons as it flew by the object on Jan. 1, 2019. (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Roman Tkachenko)

With NASA approval in 2016, New Horizons' mission was extended to take a closer look at a Kuiper Belt object dubbed 2014 MU69, which NASA nicknamed Ultima Thule and is now officially known as Arrokoth.

In September 2017, New Horizons concluded a planned five-month hibernation period in preparation for the probe's extended mission. Until December of that year, New Horizons took several photos of Kuiper Belt objects. Notably, some of New Horizons' 2017 photographs included images of objects 2012 HZ84 and 2012 HE85.

Given New Horizons' great distance from Earth at the time (3.79 billion miles or 6.12 billion km from Earth), the spacecraft's images became the farthest photos ever captured by a spacecraft flying from Earth. The previous record had been held by Voyager 1, which took the famous "Pale Blue Dot" image of Earth on Feb. 14, 1990, from 3.75 billion miles (6 billion km) away.

New Horizons flew by Arrokoth on Jan. 1, 2019. The little world is so far from Earth that NASA didn't know until 10 hours later if the flyby was successful. At its closest approach, New Horizons zoomed by Arrokoth at a distance of about 2,000 miles (3,540 km), which was 5,800 miles (9,300 km) closer than the craft flew by Pluto.

The first photos of Arrokoth showed that it was made up of two lobes, each almost spherical. NASA nicknamed the largest lobe Ultima and the smallest one Thule. These lobes appeared red (likely fading over time due to radiation) and actually used to be separate objects, which, over time, were gravitationally attracted to one another.

New Horizons is so far out in the Kuiper Belt that sending data back to Earth takes significant time. Investigators have said it will take roughly 20 months for all of the Arrokoth data to flow back to Earth, which means new information continued to arrive up until late 2020.

By March 2019, enough data had been sent to Earth that researchers could create a map showing the complex geology of Arrokoth. It's possible that several different building blocks converged to form the object, although that information is being investigated further; the lumpy surface of Arrokoth still was puzzling investigators. The team also released a 3D image that shows the relative sizes of different lumps and bumps on Arrokoth. The encounter with the small body is also telling us a lot about how planets are born which may end a long-standing debate.

Additional resources

Learn more about the New Horizons mission from NASA.
Find out where New Horizons is right now.
Watch a documentary about New Horizons made by the Johns Hopkins University Applied Physics Laboratory.

This article was updated on Oct. 13, 2021, by All About Space staff writer Daisy Dobrijevic.

]]> https://www.space.com/18377-new-horizons.html 3Ao7yZTaCBAYVFjWMLdEsn Wed, 20 Oct 2021 15:12:07 +0000 Wed, 20 Oct 2021 15:12:07 +0000 <![CDATA[ NASA celebrates New Horizons' historic Pluto flyby in 2015 with awesome new videos ]]> NASA has released new visualisations of the dwarf planet Pluto and its largest moon Charon to commemorate the first-ever up close exploration of the distant worlds, which took place six years ago when the New Horizons probe performed its historic flyby.

The new videos take viewers on simulated flights over the two faraway members of the solar system, revealing unprecedented details. Although Pluto and Charon are more than 3 billion miles (4.8 billion kilometers) from Earth, the new video shows features as small as 230 feet (70 meters) on their surface.

"These new high-resolution flyover videos are incredible," New Horizons principal investigator Alan Stern, of the Southwest Research Institute in Boulder, Colorado, said in a statement. "They aren't just scientifically valuable, but they are also engaging, which is why we want to share them with the public."

The videos show the nitrogen-laden ice sheet in the Sputnik Planitia impact basin, which forms part of Pluto's famous "heart." That feature covers a large portion of the dwarf planet's southern hemisphere.

When creating the videos, New Horizons science team member and moviemaker Paul Schenk, from the Lunar and Planetary Institute in Houston, used some of the sharpest images and topographic data acquired by New Horizons during its historic flyby on July 14, 2015, NASA said in the statement.

The black-and-white images were taken by the probe's Long Range Reconnaissance Imager (LORRI) as the spacecraft zipped by the dwarf planet at more than 30,000 mph (48,000 kph).

The Pluto flyover starts near the center of the Sputnik Planitia ice sheet, revealing the small pits covering its surface. Viewers are then taken to the basin's rugged southeastern rim, which is carved in ice 2 miles (3.5 kilometers) deep.

Schenk also added color data from New Horizons' Multispectral Visible Imaging Camera (MVIC) to bring out the reddish hues in Pluto's highlands.

The flight over Charon shows the low-lying icy volcanic plains in the moon's Vulcan Planitia, then moves toward the fractured northern plains some 300 miles (500 km) away. Prominently visible are several mountains that rise about 1.5 to2.5 miles (3 to4 km) above the volcanic plains. The images in this narrow strip show surface details as small as about 450 feet (140 m) across, NASA officials said.

New Horizons flew by an even more distant world, the small Kuiper Belt object Arrakoth, on New Year's Day 2019. And the probe isn't done yet; it continues its journey through the outer edges of the solar system on an extended mission, which may include a third flyby if the team can find a suitable target. The probe is currently located some 4.6 billion miles (7.4 billion km) from Earth.

Follow Tereza Pultarova on Twitter @TerezaPultarova. Follow us on Twitter @Spacedotcom and on Facebook.

]]> https://www.space.com/nasa-new-horizons-pluto-charon-videos NMbpttPrkXx5YazgetqDhc Fri, 16 Jul 2021 14:00:33 +0000 Thu, 22 Jul 2021 20:39:12 +0000 <![CDATA[ Tantalizing Pluto views suggest active surface but won't be seen again for 161 years ]]> For a brief moment in time in July 2018, the solar system aligned to show Earth the fully sunlit disk of Pluto, an arrangement that won't occur again for 161 years.

Planetary scientist Bonnie Buratti was ready: She had been waiting for a decade for the opportunity to catch the rare sight in hopes of filling a gap in knowledge that even the carefully planned New Horizons mission couldn't tackle. The result is an enigmatic plot of light from Pluto and its moon, Charon.

"We grasped this once-in-a-lifetime — well it's once in more than a lifetime, once in two centuries — opportunity to see Pluto fully illuminated," Buratti, who works at NASA's Jet Propulsion Laboratory in California and is the lead author on a new paper presenting the observations, told Space.com.

Observations of a solar system body at and around the point of its maximum illumination allow scientists to measure what they call the "opposition surge," a sudden increase in brightness of an object as it is fully illuminated, disproportionate to the extra sliver of surface area being illuminated.

And opposition surge isn't just a curious optical phenomenon: Scientists believe the pattern of the surge is influenced by the density of material on a world's surface. "By looking at how much an object brightens when it gets full, you can tell something about the surface texture and what the surface is like — is it fluffy? Is it snowy? Is it compact?" Buratti said.

For example, the opposition surge of the full moon is caused by the loose, dusty regolith at its surface, she said. "These particles cast shadows and those shadows rapidly disappear as the face becomes illuminated to the observer."

A fully illuminated Pluto is difficult to catch from Earth because the inclination of the dwarf planet's orbit compared to our own. Skywatchers use the term "opposition" to refer to the point in Earth's year when a particular solar system object appears opposite to the sun in our skies. However, a celestial body doesn't necessarily appear fully illuminated at that time, particularly something like Pluto that is often above or below the plane of Earth's orbit around the sun.

Hence the 161 year wait for the next such opportunity and Buratti's care to make a note of the 2018 opportunity so far in advance. She and her colleagues arranged for time using the 200-inch Hale telescope at the Palomar Observatory near San Diego. The Hale telescope is equipped with an optics system that could pick apart Pluto and Charon, rather than seeing one blob of the two worlds.

And the team managed to catch super-illuminated observations of Pluto on July 12, 2018, as well as other days that month and in July 2019. Buratti and her colleagues had more measurements planned for last summer, but the COVID-19 pandemic shut down the observatory.

The researchers still aren't allowed to use the telescope in person, but finally, Buratti and her colleagues again have observations on the calendar, beginning on Saturday (June 19). She hopes those measurements, plus more next month and in October, will clarify just how Pluto's opposition surge occurs, giving scientists the details they need to understand what might be happening on the ground to cause the visual effect.

Buratti said her suspicion is that the sharp opposition surge is related to how dynamic a world the New Horizons spacecraft discovered during its 2015 flyby. "Pluto is much more active than we thought," she said. "We saw stuff we never saw before there."

It's the first solar system world beyond Earth known to sport glaciers, for example. Ices vaporize and refreeze, sometimes moving between Pluto and Charon in the process. "There might be snow on it [Pluto], there's a lot of frost moving around, it might have a really fluffy, textured surface."

Although the relatively close alignment of spacecraft flyby and full illumination from Earth is a pure coincidence, Buratti said the combination of observations is another example of how planetary science thrives best when using ground-based and space-based tools in tandem.

New Horizons saw night-side and halfway illuminated views of Pluto during its maneuver, she noted, but couldn't see the fully illuminated disk because of the trajectory of its brief flyby. "You combine it with these ground-based observations and you have the full thing, you have the full package," she said. "These are totally complementary."

And for Buratti, the new observations are a poignant reminder of her own work during the New Horizons flyby, since it's rare that scientists get to use equipment powerful enough to differentiate Pluto and Charon when observing the pair from Earth.

"We saw Pluto and Charon separately for the first time since the encounter," Buratti said. "It's kind of emotional for me ... Here's a thing that was just a point of light, and then in a day or two it becomes this geologic world and you feel like you're there. It's an intimate thing. But then it goes back to being a point again."

The observations are described in a paper published June 8 in the journal Geophysical Research Letters.

Email Meghan Bartels at mbartels@space.com or follow her on Twitter @meghanbartels. Follow us on Twitter @Spacedotcom and on Facebook.

]]> https://www.space.com/pluto-fully-illuminated-observation-suggests-active-surface gnP65hgsgQoFb54NnfeKt9 Thu, 17 Jun 2021 10:55:04 +0000 Fri, 25 Jun 2021 16:33:21 +0000 <![CDATA[ NASA's New Horizons Pluto spacecraft is still exploring, 50 AU from the sun ]]> New Horizons is about to reach some very rarefied space, but don't expect the NASA probe to rest on its considerable laurels.

On Saturday night (April 17), New Horizons will reach 50 astronomical units (AU) from the sun, a distance achieved by just four other operational probes in the history of spaceflight. (One AU is the average Earth-sun distance — about 93 million miles, or 150 million kilometers.)

The milestone is an occasion to celebrate and appreciate New Horizons' epic mission, which gave humanity its first up-close looks at Pluto in July 2015 and followed that up with a flyby of Arrokoth, an even more distant world, three and a half years later.

Destination Pluto: NASA's New Horizons mission in pictures

"When I stop from all the day-to-day hubbub of planning and managing and data analysis and budgets and all those things, just stop and think what we've accomplished as a team, it's really inspiring," New Horizons principal investigator Alan Stern told Space.com. "Sometimes I want to pinch myself."

But there's plenty of reason to look ahead as well as back, because New Horizons is far from done. Though it's been streaking through space for 15 years, the probe remains in perfect health, Stern said, and it could continue to study its exotic environs for many years to come.

"We have power and fuel to go on into the late 2030s," said Stern, who's based at the Southwest Research Institute in Boulder, Colorado. "So, we're kind of halfway into this mission, in terms of what's possible from an engineering standpoint."

New Horizons is powered by a radioisotope thermoelectric generator (RTG), which produces electricity from the heat emitted by the radioactive decay of plutonium-238. RTGs have powered most other NASA deep-space probes as well, including the four that crossed the 50-AU threshold before New Horizons did — Pioneer 10, Pioneer 11, Voyager 1 and Voyager 2.

Pioneer 10 and 11 ceased operations years ago, but the two Voyagers remain active today, more than 40 years after launch. Both are exploring interstellar space: Voyager 1 is currently about 152 AU from Earth, and Voyager 2 is nearly 127 AU from us.

The small Kuiper Belt object Arrokoth, as seen by NASA's New Horizons probe during its flyby on Jan. 1, 2019. (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Roman Tkachenko)

A very long journey

New Horizons' journey has been three decades in the making, and it's full of twists and turns. Stern and his colleagues began developing a Pluto project in the late 1980s, but the $720 million mission didn't gain official approval until the early 2000s. (For much more about the mission's tortuous history, read Stern and planetary scientist David Grinspoon's 2018 book, "Chasing New Horizons.")

New Horizons launched in January 2006, tasked with performing the first-ever flyby of Pluto. The distant dwarf planet had been mysterious since Clyde Tombaugh discovered it in 1930, appearing as but a fuzzy blob in even the best photos NASA's Hubble Space Telescope could muster.

New Horizons aced its highly anticipated flyby on July 14, 2015, zooming within 7,800 miles (12,550 km) of Pluto's frigid surface. The observations made by the probe during this close encounter transformed Pluto from that fuzzy blob into a real place — and a stunningly diverse and interesting place at that, featuring towering water-ice mountains, bizarre "bladed terrain" and a giant nitrogen-ice plain that makes up one lobe of a now-famous "heart."

After the flyby, New Horizons continued to collect data about its surroundings, the ring of widely spaced, frigid bodies beyond Neptune's orbit known as the Kuiper Belt. The probe studied its local environment, observed a number of Kuiper Belt objects (KBOs) from a distance and, on Jan. 1, 2019, performed its second close flyby, this time of a small KBO.

During that New Year's Day encounter, New Horizons zoomed within a mere 2,200 miles (3,540 km) of Arrokoth, which was about 1 billion miles (1.6 billion km) beyond Pluto's orbit at the time. The returns of this close encounter, the centerpiece of the probe's ongoing extended mission, were perhaps even more surprising than the Pluto data: The 22-mile-wide (36 km) Arrokoth looks like a flattened, reddish space snowman, with two distinct lobes.

New Horizons' observations show that Arrokoth is a pristine and primordial object, a planetary building block left over from the solar system's very early days. And its two lobes were likely once distinct objects, which came together in a gentle merger, mission team members have said.

"Both of our main targets turned out to be scientific wonderlands — beyond our wildest expectations in both cases," Stern said.

Looking for flyby target number three

The New Horizons team has already begun searching for another KBO along the spacecraft's path, using photos captured by powerful instruments such as the Subaru Telescope in Hawaii. Stern stressed that a third flyby is a longshot, given how thinly populated the Kuiper Belt is, but he and his colleagues are doing all they can to boost their odds.

For example, mission team members J.J. Kavelaars and Wes Patrick recently began applying machine-learning techniques to the hunt for KBOs to study, both from a distance and up close.

When the duo "reran the 2020 search data through their new software tools, it not only worked 100 times faster, but it turned up dozens of new KBOs that human searchers had not found in the search images!" Stern wrote in a mission update last month. "We'll be taking advantage of this important new tool again later this year, and next year and after that as well."

Even if no suitable flyby target turns up, New Horizons will have plenty to do over the coming months and years. The probe has already eyed nearly 30 KBOs to date from afar, Stern said, and will study three more next month if all goes according to plan.

The May campaign will be "another brick in the wall of building up a statistically relevant collection of KBOs that we have studied in ways that you cannot do except by being in the Kuiper Belt, either by dint of the close range or as a result of the different angles that we see things at," Stern said. "We're building up this database. It's a legacy."

New Horizons will do other work as well. It will continue gathering data about Uranus and Neptune, for example, and keep characterizing its Kuiper Belt environment, a realm that very few probes have explored to date. And, provided it stays healthy and NASA continues to approve mission extensions, New Horizons will teach scientists about the realms beyond the Kuiper Belt, the outer edge of which is thought to lie about 70 AU from the sun.

New Horizons will reach that boundary in the late 2020s, Stern said. The spacecraft will likely be able to get to 100 AU or so by the time its power runs out in the late 2030s, further cementing its spot in exploration history.

"We said we would build a spacecraft that could fly across the solar system and explore new worlds," Stern said. "And we did that, and we're still doing that. But when I utter the words — they sound like science fiction, but they're not."

Mike Wall is the author of "Out There" (Grand Central Publishing, 2018; illustrated by Karl Tate), a book about the search for alien life. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook.

]]> https://www.space.com/new-horizons-50-astronomical-units-milestone kfZZu9JPbuehVaBCX4NqKG Sat, 17 Apr 2021 12:29:14 +0000 Thu, 22 Apr 2021 23:20:09 +0000 <![CDATA[ NASA's New Horizons probe reaches rare distance, looks out to farthest Voyager ]]> New Horizons is a long, long, long way from home.

Fifteen years after launching from Earth at a record speed, and six years since it became the first-ever spacecraft to fly by Pluto, NASA's New Horizons is about to reach a mile marker that only four other robotic probes in history have surpassed.

On Saturday (April 17) at 8:42 p.m. EDT (0042 GMT April 18), New Horizons will reach 50 AU (astronomical units) from the sun — or 50 times the distance the Earth is from the sun. That is 4.65 billion miles (7.5 billion kilometers). At 50 AU, it will take more than 6.5 hours for signals sent from New Horizons to reach Earth, and that is while traveling at the speed of light.

Destination Pluto: NASA's New Horizons mission in pictures

"I just think of the enormity of it," Alan Stern, New Horizons principal investigator at the Southwest Research Institute in Boulder, Colorado, said in an interview with collectSPACE.com. "It hasn't been done in a generation, since the Voyagers crossed these distances, and we're the only spacecraft out there in the outer heliosphere and the Kuiper Belt."

Currently in the Kuiper Belt beyond Pluto, NASA's New Horizons is just one of five spacecraft to reach 50 AU (astronomical units), or 50 times the distance between the sun and Earth, on its way out of the solar system. (Image credit: NASA/JHUAPL/SwRI)

Way out there

New Horizons is the fifth most distant spacecraft from Earth.

Pioneer 10, which was launched in 1972 and was the first probe to pass through the asteroid belt and to fly by Jupiter, reached 50 AU on Sept. 22, 1990. Today, it is approximately 129 AU from Earth.

Its sister ship, Pioneer 11, reached 50 AU a year later in 1991. It was launched in 1973 and in addition to flying by Jupiter, was the first to make direct observations of Saturn. It is now about 105 AU from Earth.

NASA launched Voyager 1 on Sept. 5, 1977, 16 days after its twin, Voyager 2. Voyager 1 studied Jupiter and Saturn, while Voyager 2 also encountered Uranus and Neptune. Voyager 1 today is 152 AU from Earth. Voyager 2 is at 127 AU. While Pioneer 10 and Pioneer 11 ceased operations years ago, both Voyagers remain active today.

The Pioneers and the Voyagers are so far out today that none of them are the nearest probe to New Horizons. NASA's Juno spacecraft, in orbit around Jupiter, is at this point closer.

"In the very distant future, we will be so far from everybody else that we will be closer to the Voyagers and the Pioneers, but we will never pass them because three of the four are going faster than us," said Stern. "Right now, we are almost 100 AU from Voyager 1."

To underscore how far Voyager 1 had traveled, NASA pointed the probe's camera back toward the inner solar system in 1990 when it was approximately 40.11 AU from Earth. The resulting mosaic image, now known as the "Family Portrait," captured six planets — Venus, Earth, Jupiter, Saturn, Neptune and Uranus — as just a few pixels of light each.

At 50 AU from the sun, New Horizons could not do the same.

"The math tells us that would burn out our camera because we would be pointed at the sun," Stern said, noting that even at such great a distance, the sun remains too bright for its long-range reconnaissance imager, which was calibrated for the dimly lit encounter with Pluto. "So we don't want to do that until we are past the Kuiper Belt years from now."

Instead, Stern and his team pointed New Horizons toward Voyager 1, marking the first time that a spacecraft in the Kuiper Belt photographed the location of an even more distant spacecraft now traveling through interstellar space.

"Of course, we didn't see Voyager 1 because it is too faint, but we imaged the star field," Stern told collectSPACE. "We looked with the camera to where the farthest spacecraft is and took a picture of that star field from our position in the Kuiper Belt. It is just hauntingly beautiful to me, even though it is just a picture of stars."

"This is an homage to Voyager's pioneering mission, in addition to marking what we are doing," he said.

Voyager at 40: 40 photos from NASA's epic 'Grand Tour' mission

To mark reaching 50 AU, NASA's New Horizons pointed its camera in the direction of Voyager 1 (marked with a yellow circle). At about 100 AU from New Horizons when this image was taken, Voyager 1 was too faint to be resolved. (Image credit: NASA/JHUAPL/SwRI)

Over the hill

More than just a round number milestone, reaching 50 AU means that everything New Horizons does now is exceeding its planned design lifespan.

"One of the first things you do when designing a spacecraft is set requirements, and one we had to set was what the maximum distance was we were designing the spacecraft to operate at," said Stern. "Now, you always build in margins so you can do better, but we had to have some number so if we crossed that goal line, we could declare victory — that the spacecraft had met its design objectives."

"That goal line was 50 AU," said Stern.

New Horizons flew by Pluto, returning the first close-up look at the world and its moons, in July 2015, when the spacecraft was 39.2 AU from the sun. Then, on New Year's Day 2019, New Horizons made the farthest flyby in history (to date), capturing the first close-up observations of a small Kuiper Belt object ("Arrokoth") at a distance of 43.4 AU from the sun.

"We're still getting data back from that flyby," said Stern. "Meanwhile, as we fly across the Kuiper Belt, we're doing three other things: we're studying the heliospheric environment, the plasma, the dust and the gas; we're studying other Kuiper Belt objects, we know have more than 30 that we have observed in ways you cannot from Earth or from any other spacecraft; and we're using the Subaru telescope in Hawaii, which is one of the largest telescopes in the world, to find new Kuiper Belt objects to study and hoping we find a flyby target, because we still have fuel in the tank and are capable of doing another flyby."

The hope is to find another target before New Horizons runs out of power. Though it draws its electricity from a nuclear battery (a radioisotope thermoelectric generator, or RTG), its plutonium power supply generates 33 watts less every decade. By the late 2030s, when New Horizons will be at or near 100 AU from the sun, it may be too low on power to operate.

Even if New Horizons does not make it to 100 AU, Stern is impressed with how far the mission has gone and even more so with how much its team has been able to achieve.

"When the Voyagers flew, their team was 450 people. New Horizons is doing this on about 50 bellybuttons, so about 10 times smaller," he said.

"When I think about what our team has accomplished over these 15 years with one spacecraft and no backup, going all the way out there to study Pluto for the first time, the Kuiper Belt for the first time and now pass the 50 AU marker where it was designed to be its maximum distance, it just sounds like science fiction to me," said Stern. "I have to pinch myself that this group of people were actually able to do this thing, it is so much larger than life."

]]> https://www.space.com/new-horizons-spacecraft-50-au-voyager-photo vPjUHqPD2kGAEjPeYiZrcL Thu, 15 Apr 2021 22:01:06 +0000 Thu, 22 Apr 2021 23:12:53 +0000 <![CDATA[ Pluto's atmosphere gets its blue haze from icy organic compounds, study suggests ]]> The haze shrouding Pluto might be made up of ice crystals possessing cyanide hearts, a new study finds.

Hazes, which are made of tiny motes of dust, smoke, ice and other substances, are not unique to Earth — scientists have detected hazes enveloping Mars, Venus, Saturn and Jupiter.

Nor are hazes limited to planets. Saturn's largest moon Titan, the only moon known to have clouds, is cloaked in a thick orange haze similar in makeup to smog on Earth. NASA's Voyager 2 spacecraft also detected haze in the atmosphere of Neptune's largest moon Triton.

NASA's New Horizons mission, which flew by Pluto in 2015, unexpectedly revealed Pluto also possesses haze hugging the dwarf planet's frozen surface. Since Pluto, Titan and Triton are all icy worlds with atmospheres rich in nitrogen, methane and carbon monoxide, researchers had thought they might all possess similar kinds of hazes.

Previous research found Titan's haze was the result of solar ultraviolet rays triggering chemical reactions in the icy moon's upper atmosphere. These created simple organic compounds that went on to help form ever larger and more complex organic molecules.

However, scientists now find the hazes on Pluto and Triton might have significantly different origins than Titan's.

NASA's Voyager 2 spacecraft captured dark streaks produced by geysers visible on the icy surface of Triton's south polar region. (Image credit: NASA/JPL)

"Although Titan and Pluto seem very similar, their haze properties can be drastically different," study lead author, Panayotis Lavvas, a planetary scientist at the University of Reims Champagne-Ardenne in Reims, France, told Space.com.

When the researchers analyzed computer models of haze formation, they discovered that if the same chemical reactions at work on Titan happened on Pluto, they could only create about half the haze particles that prior work detected on the dwarf planet. (Since Pluto's atmosphere is roughly 175 degrees Fahrenheit, or 80 degrees Celsius, colder than Titan's, its atmospheric chemistry runs slower.)

In the new study, Lavvas and his colleagues suggest that as on Titan, sunlight triggers chemical reactions in Pluto's upper atmosphere, forming simple compounds such as hydrogen cyanide, a molecule made up of one hydrogen, one carbon and one nitrogen atom. Their models suggested hydrogen cyanide might freeze to produce tiny ice particles.

NASA's Cassini spacecraft looks toward the night side of Saturn's largest moon and sees sunlight scattering through the periphery of Titan's atmosphere and forming a ring of color. (Image credit: NASA/JPL-Caltech/Space Science Institute)

As these microscopic ice particles settle downward due to gravity, other gases condense around these seeds to coat them. As such, haze particles on Pluto may be largely made of a variety of ices, instead of more complex organic compounds as on Titan. The sizes, amounts and atmospheric distributions of these ice grains in the computer models closely match those of the haze particles detected on Pluto, the scientists noted.

In addition, these ice particles on Pluto should interact less with incoming solar energy than haze particles on Titan, the researchers said. As such, they should play a smaller role in controlling heat in Pluto's atmosphere than previously thought, Lavvas said.

When it comes to Triton, since it possesses an even colder atmosphere than Pluto's, the scientists noted its hazes should prove even icier.

"This comparison of Titan, Pluto and Triton illuminates the important differences in the mechanisms of haze formation in planetary atmospheres," Lavvas said.

The scientists detailed their findings online Dec. 21 in the journal Nature Astronomy.

Follow Charles Q. Choi on Twitter @cqchoi. Follow us on Twitter @Spacedotcom and on Facebook.

]]> https://www.space.com/pluto-blue-haze-organic-compounds DzxejNAAjqAQTFFnF7RkPL Tue, 19 Jan 2021 12:15:42 +0000 Wed, 20 Jan 2021 01:58:57 +0000 <![CDATA[ New Horizons Pluto probe leader Alan Stern is going to space with Virgin Galactic ]]> Virgin Galactic just added a big-name scientist to its passenger list.

Alan Stern, who leads NASA's New Horizons mission to Pluto and beyond, has been selected to fly aboard SpaceShipTwo, Virgin Galactic's suborbital space plane.

It won't just be a pleasure cruise: Stern was chosen via NASA's Flight Opportunities program to conduct agency-funded research on the future flight, which has yet to be scheduled.

"This is the first selection of a private-sector researcher to fly with NASA funding on commercial vehicles," Stern, a planetary scientist at the Southwest Research Institute (SwRI) in Boulder, Colorado, said in a statement on Wednesday (Oct. 15), when the news was announced.

He described his selection as a "potential sea change" that could pave the way for much more extensive human-tended research in space down the road.

The two-pilot, six-passenger SpaceShipTwo is hauled aloft by a carrier plane called WhiteKnightTwo, which drops the space plane at an altitude of about 50,000 feet (15,000 meters). SpaceShipTwo then fires up its rocket motor and makes its own way to suborbital space.

Passengers and scientific payloads along for the ride will get to experience a few minutes of weightlessness and see the curvature of Earth against the blackness of space. More than 600 customers have booked a seat aboard SpaceShipTwo, at a ticket price (most recently) of $250,000, Virgin Galactic representatives have said.

Virgin Galactic is building several SpaceShipTwo vehicles and has another one, called VSS Unity, up and running. Unity has already completed two piloted demonstration flights to suborbital space and is wrapping up its test campaign at Spaceport America in New Mexico, Virgin Galactic's commercial hub.

When Stern goes up, he will test a low-light camera to gauge its potential for future astronomical observations. His vital signs will also be monitored throughout the entire two-hour mission as a biomedical experiment, SwRI representatives said.

New Horizons principal investigator Alan Stern, who's based at the Southwest Research Institute in Boulder, Colorado. — New Horizons principal investigator Alan Stern, a planetary scientist based at the Southwest Research Institute in Boulder, Colorado, will conduct experiments on one of Virgin Galactic's suborbital missions. (Image credit: Aubrey Gemignani/NASA)

The camera tech is one of 31 newly selected experiments that will get a commercial flight test through the Flight Opportunities program. Some of these tests will occur aboard suborbital vehicles such as SpaceShipTwo and Blue Origin's New Shepard craft, while others will ride on high-altitude balloons and airplanes that induce brief periods of microgravity via parabolic flight. You can read about all the experiments from NASA here.

The coming mission will be the first spaceflight for Stern, a former NASA science chief who has been on 29 different space-mission science teams during his long and varied career.

"Going to work in space myself for the first time after having spent so many years sending machines there to do the research for me is going to be a major career highlight, and something I am honored to be selected for," he said in the same statement. "But I hope this is just the first of a steady stream of flights by SwRI researchers doing work in space in the years and decades ahead."

Mike Wall is the author of "Out There" (Grand Central Publishing, 2018; illustrated by Karl Tate), a book about the search for alien life. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook.

]]> https://www.space.com/virgin-galactic-alan-stern-suborbital-flight Dba3XB2F93DRVgQZR5ufvD Thu, 15 Oct 2020 11:46:12 +0000 Thu, 15 Oct 2020 11:46:15 +0000 <![CDATA[ 2014 MU69: Arrokoth, the most distant object ever explored ]]>

After its famous flyby of Pluto in July 2015, NASA's New Horizons spacecraft made history a second time when it buzzed the most distant object ever explored: 2014 MU69.

"We set a record! Never before has a spacecraft explored something so far away," Alan Stern, the New Horizons principal investigator, said after the flyby. "I mean, think of it. We're a billion miles further than Pluto, and now we're going to keep going into the Kuiper Belt."

Both Pluto and 2014 MU69 lie within the Kuiper Belt, a collection of icy rocks that surrounds the outer reaches of the solar system. These objects are thought to be pristine samples from the early solar system, cast out into the boundary zone through gravitational interactions with the larger objects that would grow into planets. Examining them should reveal insight into what was happening in the solar system in the first stages of its lifetime.

Previously known by its nickname Ultima Thule (pronounced TOOL-ie), MU69, now officially named Arrokoth, was the first object in space to be explored by a spacecraft that launched before the object's discovery.

Beyond Pluto

As early as 2003, the National Academy of Sciences' Planetary Decadal Survey strongly recommended that the visit to Pluto include flybys of small Kuiper Belt objects (KBOs). Observing multiple targets would provide greater insight into the previously unexplored segment of the solar system. New Horizons launched in 2006 with extra fuel for such a flyby, and its power and communications systems are prepared to work at distances beyond Pluto's orbit for years to come.

In 2011, mission scientists used ground-based telescopes to begin searching for a second target, but none of the new discoveries were within the reach of New Horizons. In 2014, the Hubble Space Telescope joined the search, locating five potential objects. One of them was 2014 MU69, which was labeled 1110113Y after its June 26, 2014, discovery and also called PT1 ("potential target 1") after its elevation to one of two possible destinations. In August 2015, the New Horizons team selected 2014 MU69 as its next potential target.

"2014 MU69 is a great choice because it is just the kind of ancient KBO, formed where it orbits now, that the Decadal Survey desired us to fly by," Stern said in a statement. "Moreover, this KBO costs less fuel to reach [than other candidate targets], leaving more fuel for the flyby, for ancillary science, and greater fuel reserves to protect against the unforeseen."

MU69 lies about 1 billion miles (1.6 billion kilometers) beyond Pluto.

Naming 2014 MU69

In 2017, the New Horizons team requested suggestions from the public for a nickname for the KBO as part of an outreach campaign. The final decision, Ultima Thule, is a term used in medieval times that means "beyond the known world." The nickname was submitted by about 40 different people, NASA officials said.

"MU69 is humanity's next Ultima Thule," Stern said when the name was announced.

The nickname s pu rred controversy because of its historical use by Nazi forerunners and modern use by extremist groups. However, the New Horizons team decided to stick with the nickname despite the potentially negative connection.

"I've said it a number of times, I think New Horizons is an example — one of the best examples in our time — of raw exploration, and the term Ultima Thule, which is very old, many centuries old, possibly over a thousand years old, is a wonderful meme for exploration," Stern said after the flyby. "That's why we chose it. I would say that just because some bad guys once liked that term, we're not going to let them hijack it."

However, in November 2019, mission team members announced that the official name of 2014 MU69 would be Arrokoth, a word that means "sky" in the Powhatan/Algonquian language.

"The name 'Arrokoth' reflects the inspiration of looking to the skies and wondering about the stars and worlds beyond our own," Stern said in a statement. "That desire to learn is at the heart of the New Horizons mission, and we're honored to join with the Powhatan community and people of Maryland in this celebration of discovery."

Arrokoth, a Kuiper Belt object 4 billion miles from Earth, is seen by NASA's New Horizons spacecraft on Dec. 31, 2018, just hours before the probe's flyby closest approach on Jan. 1, 2019. It is the most distant object ever visited by a spacecraft. (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

Before the flyby

Astronomers used the help of three different stars to study Arrokoth before its arrival. When an object like a KBO travels between Earth and a star, astronomers can use the starlight to study the distant target, a technique called stellar occultation. Arrokoth traveled between Earth and several different stars — one each day — on June 3, July 10 and July 17, 2017. Each event lasted only 2 seconds or so and was only visible from a narrow band of land and sea on Earth.

"This effort — spanning six months, three spacecraft, 24 portable ground-based telescopes and NASA's SOFIA airborne observatory — was the most challenging stellar occultation in the history of astronomy, but we did it!" Stern said. "We spied the shape and size of 2014 MU69 for the first time, a Kuiper Belt scientific treasure we will explore just over 17 months from now. Thanks to this success, we can now plan the upcoming flyby with much more confidence."

Measurements from all three of the 2017 observations revealed that Arrokoth wasn't orbiting where it was expected. And, a small blip during the July 10 observation puzzled astronomers because it looked like MU69 was actually two separate objects. Together, the results suggested that MU69 wasn't spinning through space alone. Astronomers thought that MU69 may have at least one moon, and could host even more natural satellites.

"This might be the harbinger," Stern said during a news conference at the 2017 American Geophysical Union (AGU) Meeting. "It might hint that there is actually a swarm of satellites from MU69."

The New Horizons team got one final glimpse of Arrokoth before the New Horizons flyby. On Aug. 4, 2018, a final occultation was visible from Earth, seen only in Senegal and Colombia

"This occultation will give us hints about what to expect at Ultima Thule and help us refine our flyby plans," Marc Buie, the New Horizons occultation-event leader, said in a statement.

A New Year's Eve to remember

On Jan. 1, 2019, at 12:33 a.m. EST, New Horizons made its historic flyby of MU69. Team scientists and engineers gathered at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, to ring in the New Year and cheer for the moment the spacecraft buzzed the KBO. Brian May, a mission scientist and lead guitarist for the band Queen, released a new single commemorating the event. But Ultima Thule is so far away that no one knew for sure whether or not the mission had completed a successful flyby until almost 10 hours had passed.

During the flyby, New Horizons passed Ultima Thule at a distance of about 2,000 miles (3,540 km), which was 5,800 miles (9,300 km) closer than it flew by Pluto.

After the flyby, NASA released the first resolved photos of Ultima Thule, revealing that the 21-mile-long (33 kilometers) object is composed of two roughly spherical lobes. The pair are joined tightly at the neck, where material shines more brightly than along the rest of the object.

"It's a snowman, if it's anything at all," Stern said when the first color image was released.

The team decided to call the largest lobe "Ultima" and the smallest "Thule." Both lobes appear red, likely due to discoloration from deep-space radiation, researchers said. The pair most likely started out as two separate objects that gradually came together, moving less than a mile per hour.

"If you collided with another car at those speeds, you may not even bother to fill out the insurance forms," Jeff Moore, New Horizons co-investigator from NASA's Ames Research Center in California, said during the flyby.

Ultima Thule is one of a large population of objects that fill the Kuiper Belt. Eventually, similar material combined to build up moons and planets. New Horizons' images of the KBO will help provide insight into how those pieces came together to shape the solar system.

"We think what we're looking at it is perhaps the most primitive object that has yet been seen by any spacecraft, and may represent a class of objects which are the oldest and most primitive objects that can be seen anywhere in the present solar system," Moore said.

This first color photo of the Kuiper Belt object Ultima Thule reveals the object's red color as seen by NASA's New Horizons spacecraft from a distance of 85,000 miles (137,000 kilometers) during a Jan. 1, 2019 flyby. From left to right: an enhanced color image, a higher-resolution black and white image, and an overlay that combines both into a more detailed view. (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

Far out

Before New Horizons reached its second target, details of Ultima Thule were difficult to make out, even through the lens of the Hubble Space Telescope. The tiny object is less than 1 percent the size of Pluto, which was why New Horizons' close-up look was so important.

"There's so much that we can learn from close-up spacecraft observations that we'll never learn from Earth, as the Pluto flyby demonstrated so spectacularly," New Horizons science team member John Spencer, said in a statement.

"The detailed images and other data that New Horizons could obtain from a KBO flyby will revolutionize our understanding of the Kuiper Belt and KBOs."

New Horizons snapped its first image of Ultima Thule in August 2018, on the first attempt, while still more than 100 million miles (170 million km) away. At the time, the target remained one of several dots among a field of stars.

Even as the spacecraft closed in on Ultima Thule, the object remained difficult to decipher but an unusual signal hinted at its bilobed shape and rotation angle. Even in the hours before the historic event, Ultima Thule refused to yield many of its secrets. The KBO remained unresolved, barely filling two pixels worth of images. As for its then-puzzling shape, Spencer could only say, "We know it's not round."

Only after the flyby were some of the mysteries finally resolved. It turned out that the KBO rotated much like the hands of a clock facing the spacecraft, a mystery that was only resolved just before the flyby. The close encounter revealed a roughly 15-hour rotation period.

New Horizons will take 20 months to send its data back to Earth. Scientists will pore over that data for years to come to learn as much as possible about the Kuiper Belt.

And it's likely that New Horizons won't stop retrieving information about the Kuiper Belt for quite a while. The spacecraft should have enough fuel to visit another KBO. According to Stern, New Horizons will be in the Kuiper Built until 2027 or 2028.

"It would be silly not to look for another target," Stern said.

Additional resources:

This article was updated on Sept. 22, 2020 by Space.com Reference Editor Kimberly Hickok.

]]> https://www.space.com/32049-kbo-2014-mu69.html xH9GJsCanxYV66xPb3mxSo Tue, 22 Sep 2020 21:12:14 +0000 Tue, 22 Sep 2020 21:12:14 +0000 <![CDATA[ Is our solar system shaped like a deflated croissant? ]]> Our solar system's protective bubble may not be comet-shaped after all.

Scientists have traditionally posited that the heliosphere, the huge bubble of charged particles that the sun blows around itself, has a rounded leading edge, where the solar system barrels through space, with a long tail streaming behind it. But the heliosphere's true shape is weirder and more complex, a recent study suggests — something akin to a deflated croissant.

It's tough to map out the heliosphere, because its closest edge is still a whopping 10 billion miles (16 billion kilometers) from Earth. Just two spacecraft, NASA's Voyager 1 and Voyager 2 probes, have directly sampled the boundary, and two data points are far from sufficient to outline the heliosphere's contours.

So scientists have done so by other means. For example, they've studied measurements of galactic cosmic rays, super-energetic charged particles that zoom into our neighborhood from very far away. Researchers have also carefully tracked "energetic neutral atoms" that bounced sunward after interacting with the interstellar medium, the vast cosmic sea that lies beyond the heliosphere.

Such tracking has been done by a variety of spacecraft, including NASA's Interstellar Boundary Explorer and the Cassini Saturn probe. Scientists feed this information into computer models, which use it to map out the heliosphere's shape.

The recent study takes a new look at such data and also includes measurements of "pick-up ions" made by NASA's New Horizons Pluto probe, which is currently more than 4.3 billion miles (6.9 billion km) from Earth.

Pick-up ions are carried along by the solar wind, the stream of charged particles flowing continuously from the sun. (This flow is blocked by the interstellar medium to form the boundary of the heliosphere.) Pick-up ions are much hotter than the particles that make up most of the solar wind, which contributes to the heliosphere's weird shape, study team members found.

"There are two fluids mixed together. You have one component that is very cold and one component that is much hotter, the pick-up ions," lead author Merav Opher, a professor of astronomy at Boston University, said in a statement.

"If you have some cold fluid and hot fluid, and you put them in space, they won't mix — they will evolve mostly separately," Opher said. "What we did was separate these two components of the solar wind and model the resulting 3D shape of the heliosphere."

The heliosphere blocks many cosmic rays, shown as bright streaks in this animated image, from reaching the planets of our solar system. (Image credit: NASA’s Goddard Space Flight Center/Conceptual Image Lab)

That shape, they determined, is croissant-like: a curving central bulge with two jets curling away from it.

"Because the pick-up ions dominate the thermodynamics, everything is very spherical," Opher said. "But because they leave the system very quickly beyond the termination shock, the whole heliosphere deflates."

The termination shock is the heliosphere boundary region, where solar wind particles begin pressing into the interstellar medium and slow to less than the speed of sound.

Gaining a better understanding of the heliosphere's shape has multiple applications, Opher and her colleagues said. For example, the bubble blocks about 75% of galactic cosmic rays, which can damage spacecraft and the DNA of voyaging astronauts. Knowing in detail which regions of space are protected could aid mission planners. (Life on Earth doesn't have much to worry about from galactic cosmic rays; our planet's magnetic field and atmosphere provide effective shielding.)

The study was published in March 2020 in the journal Nature Astronomy.

]]> https://www.space.com/solar-system-heliosphere-shape-croissant.html N5ArmQpHsFdRQkYGNqpez5 Fri, 07 Aug 2020 16:31:30 +0000 Sun, 09 Aug 2020 13:03:54 +0000 <![CDATA[ Pluto flyby photos: New Horizons mission leader Alan Stern reveals 10 of his favorite epic views ]]> On July 14, 2015, NASA's New Horizons spacecraft zoomed within 7,800 miles (12,550 kilometers) of Pluto, capturing the first-ever up-close images of that distant and mysterious world.

The photos stunned even the most imaginative researchers and space fans, revealing a mind-boggling diversity and complexity of terrain on the frigid dwarf planet.

Take Pluto's famous "heart," whose left lobe is a nitrogen-ice glacier 600 miles wide (1,000 kilometers). New Horizons also saw huge mountains of water ice, weird "bladed terrain" sculpted out of methane ice, and enormous ice volcanoes unlike anything planetary scientists had ever seen.

Pluto revealed: 5 years ago, New Horizons gave us our 1st close look at this distant world

"I was floored," New Horizons principal investigator Alan Stern, of the Southwest Research Institute in Boulder, Colorado, told Space.com. "It is one amazing world — more than we could have asked for."

Stern has been the driving force behind New Horizons — which flew by another object, the distant Arrokoth, in 2019 and is still going strong — from its inception as a concept in the early 1990s. So, to help celebrate the fifth anniversary of the Pluto flyby, Space.com asked Stern to highlight some of his favorite photos from the epic encounter. Here are 10 that stood out to him, with captions he provided. They're presented in no particular order.

More: Destination Pluto: NASA's New Horizons mission in pictures

The flyby hemisphere

Pluto's famous — "This says it all — from the little planet with a heart to the amazing degree of geologic diversity and complexity that Pluto revealed," Stern wrote. (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

Pluto's "far" side

Pluto's mysterious far side, as seen by NASA's New Horizons spacecraft in July 2015. — "Pluto's far side was only seen in low-resolution images because Pluto rotates only once every six days and we were still three days away and millions of miles away when we best saw the far side. Still, it's incredibly different than the flyby hemisphere and beckons us to return to see this side in more detail!" (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

Glacial flow, convection, wind streaks, and dunes on a young glacier larger than Texas

Pluto's huge nitrogen-ice plain, Sputnik Planitia, as seen by NASA's New Horizons probe during its July 2015 flyby of the dwarf planet. — "Wow! Pluto's vast nitrogen glacier Sputnik [Planitia] is among the most amazing terrains in the solar system. Look closely: You will see no craters, meaning it is very young, but look some more, and see the evidence for ice convection, glacial flows, avalanches, wind streaks, water icebergs in this nitrogen ice sea, and even dune fields! Wow!" (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

Blue skies

Pluto’s haze layer displays a blue color in this image obtained by the New Horizons spacecraft's Ralph/Multispectral Visible Imaging Camera (MVIC). Image released Oct. 8, 2015. — "I love this one not only for Pluto's blue, seemingly Earth-like sky but also the fact that this image was taken after we passed Pluto, having accomplished a goal many thought we never would, and taking 26 years in the making!" (Image credit: NASA/JHUAPL/SwRI)

A rugged oblique

This Pluto flyby photo from NASA's New Horizons spacecraft shows rugged mountains and some atmospheric haze. — "This gorgeous image reveals both how rugged Pluto's terrains can be and also the dozens of layers of atmospheric haze it sports, stretching to orbital altitudes, no less!" (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

Bladed terrains

The bladed terrain on Pluto, seen here by NASA's New Horizons spacecraft during the probe's 2015 flyby of the dwarf planet, is consistent with ice-tower features called penitentes. — "Pluto's bladed mountain terrains are unlike any other we know in the solar system; they are sci-fi-like methane ice mountains stretching across much of the far side and this western-Colorado-sized piece on the eastern edge of the flyby hemisphere as well." (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

Cryovolcanoes

Old terrains

Battered, ancient terrain is visible in this Pluto flyby photo captured by NASA's New Horizons spacecraft. — "Although some parts of Pluto show no craters at all, meaning they are geologically young, other parts of the planet are old and battered, and have been dated to the time of Pluto's formation over 4 billion years ago." (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

A paleo-lake

This photo, capture by NASA's New Horizons probe during its July 2015 Pluto flyby, shows an apparent ancient nitrogen lake on the dwarf planet. — "Who ordered this? Apparently an ancient nitrogen lake sits in a rugged mountain valley, haunting forensic evidence for past epochs of far higher atmospheric pressure." (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

Snowcaps in the Kuiper Belt

Water-ice mountains capped by frozen methane, as spotted by NASA's New Horizons spacecraft during its flyby of Pluto in July 2015. — "These mountains tower as far above Pluto as the Rockies tower above our planet, but these mountains are not rock with water snow at all. They are alien: water ice mountains frosted by methane snowcaps. Imagine, snowcaps in the faraway Kuiper Belt!" (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

]]> https://www.space.com/pluto-flyby-favorite-photos-new-horizons-alan-stern.html VZAokPyLL3yWFszgZxAG36 Tue, 14 Jul 2020 11:35:20 +0000 Wed, 15 Jul 2020 20:45:01 +0000 <![CDATA[ Pluto revealed: 5 years ago, NASA's New Horizons gave us our first close look at this distant world ]]> Five years ago today, we started to appreciate just how remarkable Pluto really is.

The distant dwarf planet had been a frigid enigma since its 1930 discovery, remaining a fuzzy blob even in photos captured by the powerful Hubble Space Telescope. But everything changed on July 14, 2015, when NASA's New Horizons spacecraft zoomed within 7,800 miles (12,550 kilometers) of Pluto's icy surface.

The historic flyby completed the initial reconnaissance of the solar system's nine traditionally recognized planets and revealed a stunning complexity and diversity of terrain, from nitrogen glaciers to towering mountains of rock-hard water ice. ("Traditionally recognized" is a required qualifier here, because the International Astronomical Union "demoted" Pluto to dwarf-planet status in 2006, a decision that remains controversial to this day.)

"It is one amazing world," New Horizons principal investigator Alan Stern, of the Southwest Research Institute (SwRI) in Boulder, Colorado, told Space.com. "It even has a heart on it! Hollywood couldn't have planned it better."

Pluto flyby photos: New Horizons leader Alan Stern reveals 10 favorite views

High drama in the home stretch

The $720 million New Horizons mission launched in January 2006, speeding away from Earth at a record-breaking 36,400 mph (58,580 km/h).

Even at that blistering pace, it still took the probe 9.5 years to reach Pluto, which was about 3 billion miles (5 billion km) from Earth on the day of the flyby. And in the home stretch of that deep-space trek, New Horizons suffered a glitch that threatened to scuttle the epic encounter entirely.

The spacecraft went dark for 90 minutes on July 4, 2015, sending mission team members scrambling. But they were up to the challenge, in short order diagnosing and fixing the problem — an overloaded main computer that was trying to do two big things at once.

This high-pressure troubleshooting was far from routine, Stern stressed, praising the talent, preparation and dedication of the mission-operations team.

"We nearly lost this thing on July 4," he said. If the same glitch had cropped up just two days later, he added, it probably would have been too late to salvage the flyby.

A shockingly complex and active world

A mere three days after the glitch, New Horizons photographed a stunning sight: a huge, heart-shaped feature on Pluto's reddish surface. Pluto's now-iconic heart came into sharper and sharper focus over the ensuing days, as did the rest of the dwarf planet's "encounter hemisphere" (the side that New Horizons flew over).

And then came closest approach. On July 14, New Horizons skimmed just over Pluto, photographing and studying a staggering diversity of terrain.

For example, the heart — now known as Tombaugh Regio, after Pluto discoverer Clyde Tombaugh — is bordered in places by 2-mile-high (3 km) mountains made not of rock but of water ice. In another part of the dwarf planet, methane ice has eroded into bizarre and unique "bladed terrain." New Horizons also saw huge structures that appear to be cryovolcanoes, the largest of which is about 4.3 miles tall and 155 miles wide (7 by 250 kilometers).

All of these dramatic landscapes and more are rubbing shoulders on a world just 1,477 miles (2,377 km) wide.

"Pluto's kind of like if you took a whole bunch of national parks … and you crammed them all in a small space right next to each other," mission science team member Kelsi Singer, also of SwRI, told Space.com.

But the pretty pictures just scratch the surface of Pluto's story. For example, the left lobe of Tombaugh Regio, a 600-mile-wide (1,000 km) plain of nitrogen ice called Sputnik Planitia, sports no detectable craters. That means the region has been resurfaced very recently, which in turn shows that Pluto is geologically active.

That came as a big surprise to many scientists, who had assumed the dwarf planet is dead. Pluto is incredibly far from the sun, after all, orbiting 39.5 astronomical units (AU) from our star on average. (One AU is the average Earth-sun distance, about 93 million miles, or 150 million km.) And there's no giant planet nearby to heat the dwarf planet's innards via tidal stretching and flexing, as happens with the active moons of Jupiter and Saturn.

Indeed, the power source for Pluto's activity remains mysterious and the subject of considerable debate. For example, some researchers think heat from the radioactive decay of material in Pluto's core may be responsible. But others, including Stern, suspect the activity is driven by latent heat released by the slow, ongoing freezing of Pluto's subsurface ocean.

That's right: New Horizons' observations suggest that the dwarf planet has an ocean of salty liquid water sloshing beneath its surface. Mission data also indicate that two other ingredients crucial for life as we know it — carbon-containing organic molecules and an energy source — may be abundant on Pluto as well.

"With a straight face, you can say in 2020 that New Horizons put Pluto on the map as a world with astrobiological potential," Stern said.

The flyby led to many other discoveries as well, far too many to recount in one story. For example, New Horizons photographed gorgeously blue skies as it sped away from Pluto after the close encounter. And the probe's observations support the theory that Charon and Pluto's other four moons were formed by a long-ago giant impact in the system.

Not done yet

Scientists around the world are still analyzing data from the Pluto flyby, and they'll continue to do so for years to come.

"We were surprised by how much we were surprised by," Singer said. "There's tons of stuff left to be done."

Researchers are also still poring over information from New Horizons' second close encounter — a flyby of the 22-mile-long (35 km) object Arrokoth, conducted during the probe's ongoing extended mission.

The Arrokoth encounter occurred on Jan. 1, 2019, when New Horizons was about 1 billion miles (1.6 billion km) beyond the Pluto flyby location. The spacecraft's observations revealed that Arrokoth looks like a flattened, reddish snowman, and that the odd object formed via the very gentle merger of two primordial bodies.

The mission has therefore given us up-close looks at two very different objects in the Kuiper Belt, the ring of frigid bodies beyond Neptune's orbit. And New Horizons' flyby days may not be over just yet.

The probe remains in good health, and it has one-eighth of a tank of fuel left — the same amount that was required for the Arrokoth flyby, Stern said. So the probe might be able to squeeze in one more close encounter, provided a suitable target can be found along its flight path. The mission team recently began hunting in earnest for such a target using a variety of powerful telescopes.

"The numerical odds are long, because of the amount of fuel that's left," Stern said. "If we get lucky, then we'll have another flyby. And if we don't, we won't."

New Horizons' legacy is assured either way. The mission has pioneered the exploration of the far outer solar system, revealing just how interesting this cold, dark realm is. And it showed Pluto to be deserving of more than a mere fleeting look, stressed Stern and Singer. They've been working, with other researchers, on a concept for a mission that would orbit the dwarf planet and potentially explore other Kuiper Belt objects up close as well.

"Pluto really is such a complex world, and system of worlds, that this push to get an orbiter is really gaining traction," Stern said.

]]> https://www.space.com/pluto-flyby-new-horizons-fifth-anniversary.html F28gdXS8jwcbszsHLq3Z65 Tue, 14 Jul 2020 11:30:23 +0000 Wed, 15 Jul 2020 20:54:11 +0000 <![CDATA[ Surprise! Pluto may have had an underground ocean from the very beginning ]]> Though Pluto is now famously frigid, it may have started off as a hot world that formed rapidly and violently, a new study finds.

This result suggests Pluto may have possessed an underground ocean since early on in its life, potentially improving its chances of hosting life, researchers said.

Previous work assumed Pluto originated from cold and icy rock clumping together in the distant Kuiper Belt, the ring of objects beyond Neptune's orbit. Although there is evidence that Pluto currently possesses a liquid ocean beneath its thick frozen shell, researchers have suggested this subsurface ocean developed long after Pluto formed, after ice melted due to heat from radioactive elements in Pluto's core.

Now scientists argue that instead of a cold formation, Pluto had a hot start, one full of explosive force.

"When we look at Pluto today, we see a very cold frozen world, with a surface temperature of about 45 Kelvin [minus 380 degrees Fahrenheit, and minus 228 degrees Celsius]," study lead author Carver Bierson, a planetary scientist at the University of California, Santa Cruz, told Space.com. "I find it amazing that by looking at the geology recorded in that surface, we can infer Pluto had a rapid and violent formation that warmed the interior enough to form a subsurface water ocean."

The researchers analyzed so-called "extensional features" on Pluto's surface. Water expands as it freezes, so as Pluto's interior cooled, Pluto's surface stretched, generating recognizable structures.

The scientists compared geological observations of Pluto captured by NASA's New Horizons spacecraft, which flew by the dwarf planet in 2015, with various models of Pluto's origin and evolution. If Pluto had a cold start, its frozen shell would have experienced compression early in the world's history as heat from radioactive elements melted ice, and then extension later on after these radioactive elements broke down and Pluto cooled. However, they found the most ancient portions of Pluto's surface imaged at high resolution do not show any clear signs of compression.

Arrows mark the location of extensional faults on the surface of Pluto that indicate expansion of its crust, which scientists think is due to the freezing of a subsurface ocean. (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Alex Parker)

If Pluto had a rapid, violent formation, the heat from the colliding rocks from which Pluto coalesced would have faded relatively quickly, leading the icy shell to grow rapidly, generating extensional features early in Pluto's history. This freezing would pause as heat from radioactivity became a major factor, and resume as radioactive elements broke down, slowly creating extensional structures over time.

Extensional features the researchers saw on Pluto's icy surface — for instance, cracks in its shell, and an enigmatic system of ridges and troughs — suggest Pluto had a hot start.

"I think the most exciting implication is that subsurface oceans may have been common among the large Kuiper Belt objects when they formed," Bierson said.

These findings suggest that Pluto and other large dwarf planets in the Kuiper Belt, such as Eris, Makemake and Haumea, may have possessed subsurface oceans ever since they formed. This may have influenced the potential habitability of these distant icy worlds, the researchers said.

"At this point, we don't know the ingredients or recipe needed for life to emerge on any world," Bierson said. Still, "we think liquid water is an important ingredient, and this work suggests Pluto has had that for a long time."

Bierson did caution that New Horizons could only take high-resolution images of about half of Pluto's northern hemisphere.

"Maybe by chance we missed some ancient terrain that recorded large-scale compression," he said. "You can imagine that if you only looked at the geology of one-quarter of Earth's surface, you could learn a lot, but you would also be missing some context. For now, we can only work with what we have. It would take another spacecraft to go back and image the rest of the surface to really find out what we missed."

The scientists detailed their findings online June 22 in the journal Nature Geoscience.

Follow Charles Q. Choi on Twitter @cqchoi. Follow us on Twitter @Spacedotcom and on Facebook.

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]]> https://www.space.com/pluto-hot-formation-subsurface-ocean.html aSoNvy5LLQJRvAHvqyUC7V Mon, 22 Jun 2020 15:48:33 +0000 Sat, 27 Jun 2020 11:52:49 +0000 <![CDATA[ 'Looking at an alien sky': New Horizons probe sees shifted star positions (photos) ]]> NASA's pioneering New Horizons spacecraft has traveled so far that its view of the cosmos is noticeably different than ours.

New Horizons, which flew by Pluto in 2015 and the even more distant object Arrokoth last year, recently photographed the nearby stars Proxima Centauri and Wolf 359. In a spacecraft first, the imagery shows the two stars occupying slightly different patches of sky than they do from our perspective here on Earth.

"It's fair to say that New Horizons is looking at an alien sky, unlike what we see from Earth," New Horizons principal investigator Alan Stern, of the Southwest Research Institute (SwRI) in Boulder, Colorado, said in a statement. "And that has allowed us to do something that had never been accomplished before — to see the nearest stars visibly displaced on the sky from the positions we see them on Earth."

This two-frame animation blinks back and forth between New Horizons and Earth images of the star Proxima Centauri, clearly illustrating the different view of the sky New Horizons has from its deep-space perch. (Image credit: NASA/Johns Hopkins Applied Physics Laboratory/Southwest Research Institute/Las Cumbres Observatory/Siding Spring Observatory)

New Horizons captured the imagery on April 22 and April 23, when the probe was more than 4.3 billion miles (6.9 billion kilometers) from its home planet. That's so far away that it took 6.5 hours for the data containing the photos, moving at the speed of light, to travel from New Horizons to mission scientists' inboxes. (New Horizons isn't the farthest-flung spacecraft, however. For instance, NASA's Voyager 1 and Voyager 2 probes are both exploring interstellar space, more than 11 billion miles from home.)

Proxima Centauri and Wolf 359 are much more distant still, of course. Though Proxima Centauri is the sun's nearest neighbor, the red dwarf star is still 4.2 light-years — about 25 trillion miles (40 trillion km) — from Earth. Wolf 359 lies about 7.9 light-years from us.

New Horizons team members compared the probe's photos to imagery of Proxima Centauri and Wolf 359 captured by two ground-based telescopes — one at Siding Spring Observatory in Australia and another at Mt. Lemmon Observatory in Arizona.

This two-frame animation blinks back and forth between New Horizons and Earth images of the star Wolf 359, clearly illustrating the different view of the sky New Horizons has from its deep-space perch. (Image credit: NASA/Johns Hopkins Applied Physics Laboratory/Southwest Research Institute/University of Louisville/Harvard and Smithsonian Center for Astrophysics/Mt. Lemmon Observatory)

Both Proxima Centauri and Wolf 359 appear to jump when the two photo sets are overlaid, showcasing the "parallax effect." (You can witness this effect firsthand, by the way: Hold your index finger up at arm's length, then blink each eye successively as you stare at it.)

"The professional and amateur astronomy communities had been waiting to try this, and were very excited to make a little space exploration history," New Horizons science team member Tod Lauer, of the National Science Foundation's National Optical-Infrared Astronomy Research Laboratory, said in the same statement. "The images collected on Earth when New Horizons was observing Proxima Centauri and Wolf 359 really exceeded my expectations."

Lauer coordinated the parallax demonstration and created the new double-barreled imagery, which includes 3D views of the stars from the different perspectives. In this latter effort he had help from New Horizons deputy project scientist John Spencer of SwRI and science team collaborator Brian May, an astrophysicist who also happens to play guitar for the band Queen.

"It could be argued that in astro-stereoscopy — 3D images of astronomical objects — NASA’s New Horizons team already leads the field, having delivered astounding stereoscopic images of both Pluto and the remote Kuiper Belt object Arrokoth,” May said in the same statement.

"But the latest New Horizons stereoscopic experiment breaks all records," May added. "These photographs of Proxima Centauri and Wolf 359 — stars that are well-known to amateur astronomers and science fiction aficionados alike — employ the largest distance between viewpoints ever achieved in 180 years of stereoscopy!"

You can learn more about the experiment today (June 12): Stern, May and two other New Horizons scientists will participate in a Reddit "Ask Me Anything" session at 1 p.m. EDT (1700 GMT).

The parallax demonstration was not done for scientific purposes, Stern told Space.com (though he did note that the New Horizons imagery might find its way into textbooks that discuss the parallax effect). Rather, the main goal was public outreach and engagement, and a desire to provide us all with some cosmic poetry and perspective.

We could get more such demonstrations, and much more data, from New Horizons in the coming years. The probe remains in good health and has enough fuel to fly by yet another object in the 2020s, if a suitable target can be found and NASA approves another mission extension, Stern and other team members have said.

Mike Wall is the author of "Out There" (Grand Central Publishing, 2018; illustrated by Karl Tate), a book about the search for alien life. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook.

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]]> https://www.space.com/nasa-new-horizons-star-shift-parallax-photos.html VmE9FqawVZTQNfPKh55fFK Fri, 12 Jun 2020 14:44:55 +0000 Fri, 12 Jun 2020 15:51:57 +0000 <![CDATA[ Pluto's wispy atmosphere may be surprisingly robust ]]> The thin atmosphere of Pluto may be far more resilient than scientists thought

The dwarf planet's thin shell of air is generated by the vaporization of surface ices, which leads to the lofting of nitrogen and small amounts of methane and other gases. That vaporization is driven by sunlight, the intensity of which varies greatly during Pluto's highly elliptical, 248-year-long trek around the sun.

Many scientists have thought that Pluto's atmosphere waxes and wanes dramatically as a result, probably even collapsing completely when the dwarf planet is at its farthest from the sun. However, recently published results based on observations by NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA) may force scientists to rethink such notions.

"Now, we're questioning if Pluto's atmosphere is going to collapse in the coming years — it may be more resilient than we thought," study lead author Michael Person, director of the Massachusetts Institute of Technology's Wallace Astrophysical Observatory, said in a statement this week.

Most of what we know about that atmosphere, and Pluto itself, comes courtesy of NASA's New Horizons mission, which flew by the dwarf planet in July 2015.

Two weeks before that epic flyby, SOFIA got a much longer-range look at Pluto's air, studying the dwarf planet as it passed in front of a distant star. SOFIA, a modified Boeing 747 jet outfitted with a nearly 9-foot-wide (2.7 meters) telescope, stared as starlight streamed through Pluto's atmosphere.

This "occultation" was visible for just 2 minutes, and only from a small patch of the Pacific Ocean near New Zealand. SOFIA got into position in plenty of time initially, but the plane had to course-correct just two hours before the event when updated predictions revealed that the faint shadow would actually settle onto the waves 200 miles (320 kilometers) farther north than previously thought.

"Capturing that shadow required a bit of scramble. SOFIA has the benefit of being mobile, but the revised flight plan had to be cleared by air traffic control," William Reach, SOFIA’s associate director for science operations, said in the same statement.

"There were a few tense moments, but the team worked together, and we got clearance," Reach said. "We reached Pluto’s shadow at exactly the right time and were very happy to have made it!"

SOFIA was able to peer into the middle layers of the dwarf planet's atmosphere, gathering data in infrared and visible-light wavelengths. Two weeks later, during its flyby, New Horizons collected information about the upper and lower layers, in radio and ultraviolet frequencies.

"These combined observations, taken so close in time, have provided the most complete picture yet of Pluto’s atmosphere," NASA officials wrote in the same statement.

For example, New Horizons' imagery revealed that the atmosphere has a distinct blue tint, like the air of Earth. The color is thought to come courtesy of tiny haze particles, which reflect short-wavelength blue light preferentially.

SOFIA's observations confirmed the existence of those particles and characterized them, revealing that each fleck is just 0.06 to 0.10 microns wide, study team members said — about 1,000 times thinner than a human hair.

After analyzing these and other results — including information gathered by SOFIA's predecessor, the Kuiper Airborne Observatory, which operated from 1975 to 1995 — Person and his colleagues determined that Pluto's haze likely evolves on short timescales, fading and thickening over the course of just a few years.

This brief cycle suggests that something other than Pluto's distance from the sun is driving the abundance of haze particles. For example, periods of thick haze may result when particularly ice-rich regions of Pluto's surface get their time in the sun, the researchers said.

"There’s still a lot we don’t understand, but we’re forced now to reconsider earlier predictions," Person said. "Pluto’s atmosphere may collapse more slowly than previously predicted, or perhaps not at all. We have to keep monitoring it to find out."

The study was published online in November 2019 in the journal Icarus.

It's unclear how many more occultations SOFIA will be able to chase down: President Donald Trump's proposed budget for 2021 would eliminate funding for the program. But that's not necessarily a death sentence. No budget is final until Congress passes it, and SOFIA — a joint project of NASA and the German Aerospace Center, known by its German acronym DLR — has escaped proposed termination before.

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]]> https://www.space.com/pluto-atmosphere-hazy-resilient-nasa-sofia.html 8hewnr6uWkVMXkAiK9NQtB Thu, 14 May 2020 11:47:04 +0000 Tue, 19 May 2020 10:47:59 +0000 <![CDATA[ Arrokoth unmasked: NASA probe's 'space snowman' encounter reveals how planetesimals are born ]]> A NASA probe's epic encounter with a small body in the far outer solar system is telling us a lot about how planets are born.

On Jan. 1, 2019, the New Horizons spacecraft zoomed within just 2,200 miles (3,540 kilometers) of Arrokoth, a 22-mile-wide (36 kilometers) object in the Kuiper Belt, the ring of frigid bodies beyond Neptune's orbit.

It was the most distant planetary flyby in the history of spaceflight. Arrokoth lies 4.1 billion miles (6.6 billion km) from Earth — about 1 billion miles (1.6 billion km) farther away than Pluto, which New Horizons cruised past in July 2015.

New Horizons found Arrokoth to be a suitably exotic denizen of this far-off realm, as the mission team reported last May in a study in the journal Science detailing the flyby's initial science returns. The probe's observations revealed a remarkably red object composed of two distinct lobes, both of which are surprisingly flattened. Arrokoth thus looks like a space snowman, albeit one that's been beaten and bloodied.

That snowman shape indicates that Arrokoth formed via a merger of two separate objects, and that this coalescence happened very long ago, back when impact speeds in the outer solar system were quite low. (Collisions in the modern Kuiper Belt are too violent to produce an object with lobes as distinct and undamaged as Arrokoth's, New Horizons team members have said.)

So, Arrokoth is a primordial body — a planetary building block, or planetesimal, left over from the solar system's very early days. And each of its two lobes apparently came together in the same swirling, gravitationally collapsing cloud of dust and gas in the Kuiper Belt, far from the newborn sun, the researchers wrote in the May 2019 study.

That initial interpretation has stood the test of time, it turns out.

The mission team published three new Arrokoth papers online today (Feb. 13) in Science, reporting analyses of 10 times more flyby data than was at hand during the writing of last year's study. (It takes a while for New Horizons to beam big datasets home.) The new studies largely confirm and extend the original conclusions about Arrokoth, and they nail down the distant object's origin story.

"Arrokoth has told us how planetesimals form, and therefore made a major advance in our understanding of planet formation," New Horizons Principal Investigator Alan Stern, a co-author of all three new studies, told Space.com. "It is very decisive."

Two formation possibilities

Arrokoth's "cloud collapse" birth was far from a given. There's a prominent competing theory about planetesimal formation called "hierarchical accretion," which posits that the planetary building blocks are built up over time by high-speed collisions of objects from various locales.

Hierarchical accretion is actually the more venerable idea, dating back 70 years or so, Stern said, whereas cloud collapse (also known as "pebble accretion") was devised just at the beginning of this century.

There has been considerable debate between advocates of the two theories over the past two decades. But the three new papers show convincingly how Arrokoth was born, said Stern, who's based at the Southwest Research Institute (SwRI) in Boulder, Colorado.

"With Arrokoth, there are half a dozen lines of evidence that all point to cloud collapse, and you can't explain them with hierarchical accretion," he said.

Perhaps the strongest such evidence is provided by the object's shape. As discussed above, the relatively intact nature of the two lobes implies a very gentle collision, not a high-speed wreck.

In one of the new papers, researchers led by William McKinnon of Washington University in St. Louis performed detailed modeling of that long-ago merger. These simulations indicated that the two lobes likely formed from the same cloud of material, became a co-orbiting binary object and finally came together in a slow and non-destructive fashion. Indeed, the models peg the collision's maximum speed at around 9 mph (15 km/h), and it may have been considerably less than that.

This scenario is further bolstered by the geometric alignment of Arrokoth's two lobes, which strongly suggests that the duo orbited the same center of mass (when they were separate, free-flying objects), the scientists wrote.

This brief animation moves between two New Horizons spacecraft views of Arrokoth, the spacecraft's New Year's 2019 flyby target in the Kuiper Belt. The 3D effects come from pairing or combining images taken at different viewing angles, creating a "binocular" stereo effect, just as the separation of our eyes allows us to see three-dimensionally. The 3D information from these images provides scientists with critical insight on the object's shape and structure and, subsequently, origin. (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Roman Tkachenko)

Another of the new studies, led by SwRI's John Spencer, digs into the geology and geophysics of Arrokoth, which also point to a cloud-collapse origin. For example, the density of craters on Arrokoth indicates that the object is ancient, with a surface at least 4 billion years old. And, like McKinnon and his team, Spencer et al. found a close alignment of the two lobes, whose poles and equators are geometrically in synch. (They also determined, among other interesting finds, that the lobes aren't quite as flattened as originally believed.)

In the third paper, Will Grundy of Lowell Observatory and Northern Arizona University and his colleagues investigated Arrokoth's composition. They found that the object (which was previously known officially as 2014 MU69, and unofficially as Ultima Thule) is cold and extremely red, with methanol ice and carbon-containing organic materials on its mostly homogeneous surface. These complex organics are probably responsible for the object's red hue, the researchers wrote. (New Horizons didn't spot any water ice, but this material may still be on Arrokoth, lurking out of sight.)

This overall picture is also consistent with a cloud-collapse birth, mission team members said. For instance, the compositional similarity of the two lobes suggests they formed from the same starter material.

Born from a cloud

Stern and his fellow New Horizons team members aren't the only ones who find all this evidence convincing.

"To me, the observations of Arrokoth show that planetesimals form from collapsing clouds of pebbles," Anders Johansen, an astronomy professor at Lund University in Sweden, told Space.com via email.

"The mechanism that gathers the pebbles into such clouds to begin with is called the streaming instability," added Johansen, who was not involved in the three new studies. "It is amazing to see how Arrokoth resembles the planetesimals that we form in computer simulations of the streaming instability. So, I would say that these observations of Arrokoth provide a window to look into how planetesimals formed in the solar system more than 4.5 billion years ago."

This window could let in a great deal of light, according to Stern. He cited as a comparison the vigorous debate about the universe's origins that stretched from the 1940s through the mid-1960s. Some researchers argued for the "steady state" theory, others pushed the "constant creation" model and a third group backed the Big Bang, Stern said.

"They battled it out and battled it out and battled it out; nobody could tell who was right. And then, [Arno] Penzias and [Robert] Wilson stumbled onto the cosmic microwave background [in 1964] and settled it," he said. "Two of the three went into the dustbin, and the Big Bang has been paradigm ever since. This is equivalent in planetary science."

Johansen as well sees extension of the newly announced results beyond just Arrokoth's birth.

"In the 'pebble accretion' theory, the formation of planets happens as the largest planetesimals continue to grow by accreting pebbles," he said. "So, the fact that Arrokoth formed from a pebble cloud could mean that the solid cores of the giant planets — Jupiter, Saturn, Uranus and Neptune — formed from large planetesimals that continued to accrete pebbles. And maybe even the terrestrial planets in the solar system owe their existence to pebble accretion."

There's one notable caveat to such talk of broader applications: Arrokoth must be representative of most if not all planetesimals, and not some one-off weirdo. But this condition is likely to be met. After all, Arrokoth is similar to other Kuiper Belt objects in size, color and reflectivity, Stern said. And the odds are slim that New Horizons would randomly sample an atypical cosmic body.

Still going strong

New Horizons launched in January 2006 to give humanity its first up-close looks at Pluto, which had remained mysterious since its 1930 discovery. The probe aced that primary mission, returning imagery of the dwarf planet that revealed it to be a stunningly complex and diverse world.

The Arrokoth encounter is the centerpiece of New Horizons' current extended mission, which runs through 2021. But the probe may well have another flyby in its future.

New Horizons remains in great shape and has sufficient fuel to conduct another encounter, if the right object is found (and NASA approves another mission extension), Stern said. And, this summer, the mission team will begin a concerted search for potential future flyby targets, using the Subaru telescope in Hawaii and the Magellan and Gemini South telescopes in Chile.

There's no guarantee that this search will be successful, Stern stressed.

"It took us four years to find Arrokoth, so I'm not promising anything," he said. "But if you don't swing the bat, you can't hit the ball."

Mike Wall's book about the search for alien life, "Out There" (Grand Central Publishing, 2018; illustrated by Karl Tate), is out now. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook.

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]]> https://www.space.com/new-horizons-arrokoth-flyby-planet-formation-clues.html EwNFstmjDVUd6irH9szejF Thu, 13 Feb 2020 19:08:24 +0000 Fri, 14 Feb 2020 12:28:14 +0000 <![CDATA[ Pluto's famous heart powers icy winds on the dwarf planet ]]> Pluto's icy heart is beating.

The dwarf planet's famous heart-shaped feature, which NASA's New Horizons spacecraft discovered during its epic July 2015 flyby, drives atmospheric circulation patterns on Pluto, a new study suggests.

Most of the action comes courtesy of the heart's left lobe, a 600-mile-wide (1,000 kilometers) nitrogen-ice plain called Sputnik Planitia. This exotic ice vaporizes during the day and condenses into ice again at night, causing nitrogen winds to blow, the researchers determined. (Pluto's atmosphere is dominated by nitrogen, like Earth's, though the dwarf planet's air is about 100,000 times thinner than the stuff we breathe.)

These winds carry heat, particles of haze and grains of ice westward, staining the ices there with dark streaks.

"This highlights the fact that Pluto's atmosphere and winds — even if the density of the atmosphere is very low — can impact the surface," study lead author Tanguy Bertrand, an astrophysicist and planetary scientist at NASA's Ames Research Center in California, said in a statement.

And that westward direction is interesting in itself, considering that Pluto spins eastward on its axis. The dwarf planet's atmosphere therefore exhibits an odd "retrorotation," study team members said.

Bertrand and his colleagues studied data gathered by New Horizons during the probe's 2015 close encounter. The researchers also performed computer simulations to model Pluto's nitrogen cycle and weather, especially the dwarf planet's winds.

This work revealed the likely presence of westerly winds — a high-altitude variety that races along at least 2.5 miles (4 kilometers) above the surface and a fast-moving type closer to the ground that follows Sputnik Planitia's western edge.

That edge is bounded by high cliffs, which appear to trap the near-surface winds inside the Sputnik Planitia basin for a spell before they can escape to the west, the new study suggested.

"It's very much the kind of thing that's due to the topography or specifics of the setting," planetary scientist Candice Hansen-Koharcheck, of the Planetary Science Institute in Tucson, Arizona, said in the same statement.

"I'm impressed that Pluto's models have advanced to the point that you can talk about regional weather," added Hansen-Koharcheck, who was not involved in the new study.

New Horizons' Pluto flyby revealed that the dwarf planet is far more complex and diverse than anyone had thought, featuring towering water-ice mountains and weird "bladed" terrain in addition to the photogenic heart (whose official name, Tombaugh Regio, honors the discoverer of Pluto, Clyde Tombaugh).

The new study, which was published online Tuesday (Feb. 4) in the Journal of Geophysical Research: Planets, reinforces and extends that basic message.

"Sputnik Planitia may be as important for Pluto's climate as the ocean is for Earth's climate," Bertrand said. "If you remove Sputnik Planitia — if you remove the heart of Pluto — you won't have the same circulation."

]]> https://www.space.com/pluto-heart-powers-icy-winds.html TCiknagC8jHqLV8n3yERJB Wed, 05 Feb 2020 12:18:54 +0000 Wed, 05 Feb 2020 12:18:56 +0000 <![CDATA[ Pluto and Titan are surprisingly hazy, but scientists are fuzzy on exactly why ]]> NASA's New Horizons mission turned Pluto from a fuzzy blob into a detailed, geophysically complex world. But it's still a little fuzzy, as it turns out.

That's because when scientists looked through the flyby data, they realized the dwarf planet had a feature they didn't expect: haze. Now, with New Horizons long past the icy world, they are left trying to piece together what the visit taught us.

"It's surprising that Pluto has this fabulous haze layer," Bonnie Buratti, a planetary scientist at NASA's Jet Propulsion Laboratory in California, said on Jan. 8 during a presentation at the 235th meeting of the American Astronomical Society held in Honolulu. And from there, the mysteries continued. "We talk about Pluto being a new Mars, but it looks like it might be the new Titan as well," Buratti said.

Titan is Saturn's largest moon, and perhaps its weirdest as well. That's because, much like Earth, Titan sports features like dunes, lakes and seas — just made of very different substances than their terrestrial equivalents. And scientists think that on this strange world, organic molecules fall out of the thick atmosphere to the surface to form those dunes.

Now that they've identified haze at Pluto, Buratti said, scientists are trying to establish whether a similar phenomenon is taking place on the surface of that world as well. "The basic thing we're trying to do is make the connection between the haze and the surface," she said.

The first step is to try to figure out what that haze is made of. To do so, Buratti and a colleague compared data from Pluto, Titan and Neptune's icy moon Triton. That world has never been thoroughly studied by a nearby spacecraft, but astronomers have successfully observed it from the ground.

The scientists were able to model the three worlds to better understand their hazes, and concluded that on all three worlds, the haze consists of small, icy particles. But on Triton, that's water ice. On Pluto, a reddish tinge to the light signature scientists studied points to organic particles in that haze. "It's a factory for creating organic molecules," Buratti said of the dwarf world. "Triton is icy, but Pluto is more like Titan."

That comparison is intriguing on its own. But for Buratti, the even more compelling possibility presented by this research stretches far beyond Pluto, she said. In fact, she wonders whether the haze might spread out beyond the edge of our solar system — and beyond the current reach of our detectors.

"Since this happens on at least two objects in the solar system, maybe similar hazes might be common on exoplanets and even exomoons."

Email Meghan Bartels at mbartels@space.com or follow her @meghanbartels. Follow us on Twitter @Spacedotcom and on Facebook.

]]> https://www.space.com/pluto-hazy-organics-surprise-scientists.html gxDkLdkAZeMYHXpuKT2dZe Mon, 27 Jan 2020 11:27:22 +0000 Wed, 29 Jan 2020 00:24:38 +0000 <![CDATA[ One Year Ago, NASA's New Horizons Made the Most Distant Flyby in Space History ]]>

In the early hours of 2019, NASA's New Horizons zipped past the Kuiper Belt Object 2014 MU69, making the most distant spacecraft flyby ever performed. Over the last 12 months, researchers have teased a lot of information out of the images captured over the few hours leading up to and after the exploration of one of the most primordial objects in the solar system.

"It seems like it was just yesterday—time flies!" New Horizons co-investigator Fran Bagenal, a researcher at the University of Colorado Boulder, told Space.com by email.

Team member Kelsi Singer, a planetary scientist at the Southwest Research Center in Colorado, echoed the sentiment. "I can't believe it was already a year ago," Singer said.

Within the first week, researchers knew that MU69, now officially named Arrokoth, was made up of two flattened lobes, more like joined pancakes than a space snowman. In the intervening months, they determined the precise sizes of the lobes and their densities, measuring surface brightness and crater scars.

Video: Relive NASA's Historic Kuiper Belt Flyby of New Horizons
Related: New Horizons' Arrokoth Flyby in Pictures

A year of images

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NASA's New Horizons spacecraft flies by the Kuiper Belt object Ultima Thule on Jan. 1, 2019 in this artist's illustration. It's the furthest planetary flyby in history. (Image credit: Adrian Mann/All About Space)

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New Horizons principal investigator Alan Stern (center) celebrates with school children at the moment the spacecraft was planned to reach its closest approach to Kuiper Belt object Ultima Thule on Jan. 1, 2019 at the Johns Hopkins University Applied Physics Laboratory. It is the furthest flyby in history. (Image credit: Bill Ingalls/NASA)

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If you prefer Kuiper Belt objects appearing to dance across your screen, New Horizons has you covered there, too. (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/National Optical Astronomy Observatory)

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A new map produced by the New Horizons team appears to show the many different lumps of rock that converged to form the object nicknamed Ultima Thule. (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/ESA)

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This composite image of the small Kuiper Belt object 2014 MU69, now officially named Arrokoth, was compiled from data obtained by NASA's New Horizons spacecraft as it flew by the object on Jan. 1, 2019. The image combines enhanced color data (close to what the human eye would see) with detailed high-resolution panchromatic pictures. (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute//Roman Tkachenko)

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NASA's New Horizons spacecraft flew by the distant Kuiper Belt object Ultima Thule (2014 MU69) on Jan. 1, 2019. (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/National Optical Astronomy Observatory)

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(Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

New Horizons flew past 2014 MU69 on January 1, 2019 at 12:33 am EST, buzzing only 2,200 miles (3,538 km) above the object’s surface. When the spacecraft approached Arrokoth, all researchers had was a measurement of the object's size and orbit and a rough understanding of its reddish color and relatively unchanging brightness. The first few moments put much of that uncertainty to rest.

Arrokoth consists of two lobes. The larger lobe, nicknamed Ultima, is approximately 13.5 miles (22 kilometers) long, 12 miles (20 km) wide, and 4 miles (7 km) thick. The smaller lobe, Thule, is more circular, roughly 8.5 miles (14 km) by 8.5 miles (14 km) with a thickness of 6 miles (10 km).

According to observations, the two lobes most likely formed at about the same time more than 4.5 billion years ago, at the dawn of the solar system. While they experienced some light cratering—including a massive blow that left Maryland, an extensive crater on Ultima that stretches 4.3 miles (7 km) across the surface—Arrokoth remains relatively unscathed since its birth. Scientists expect that impacts came early in Arrokoth's lifetime, then tapered off, making it one of the most pristine bodies in the solar system.

"I find it fascinating that Arrokoth is so lightly cratered," Singer said. The dearth of scars suggests that the Kuiper Belt Object (KBO) changed very little since its early birth. Most of the craters are surprisingly large, with few mid-sized or small craters scarring Arrokoth. "That tells us that there are not a lot of small objects out there," Singer said.

The most detailed image of Arrokoth, captured just minutes before New Horizons made its closest approach on Jan. 1, 2019. (Image credit: NASA/Johns Hopkins Applied Physics Laboratory/Southwest Research Institute, National Optical Astronomy Observatory)

Its early origin was one of the primary reasons Arrokoth was selected for exploration. Scientists had hoped that they would be able to catch a glimpse of the building blocks of early solar system formation in the KBO, a hope that Arrokoth more than fulfilled. The lack of scarring around the neck, where the two lobes joined, suggest a gentle collision. This led researchers to surmise that Ultima and Thule likely formed separately at about the same time, then slowly spiraled into one another to create a single object.

"I think it's really interesting that people can look at the two parts of the object and estimate that they must have come together so slowly, almost equivalent to walking pace," Bagenal said.

Arrokoth rotates on its axis once every 16 hours as it makes its 293-Earth-year orbit around the sun. Unlike Earth, whose rotation axis is roughly perpendicular to its orbit, Arrokoth keeps its north pole pointed towards the sun, resulting in long polar days and nights when regions may receive decades of daylight or darkness.

The crescent of Arrokoth, captured when New Horizons looked back at the object after the historic New Horizons flyby of Jan. 1, 2019. (Image credit: NASA/Johns Hopkins Applied Physics Laboratory/Southwest Research Institute, National Optical Astronomy Observatory)

New Horizons also mapped the features of Arrokoth, charting its composition, bright spots, and fractures across the surface. The most volatile ices long ago escaped from the tiny object, but methanol, acetylene, ethane and hydrogen cyanide would have been retained. As radiation from the distant sun and other stars hit Arrokoth, hydrogen would have slowly been released, turning the ices into material known as tholins. On Pluto's moon Charon, an earlier target of New Horizons, tholins create the reddish cap at the north pole. They may also be responsible for the reddish color of Arrokoth.

Not all of New Horizons' data has been returned to Earth.

Although Singer said that all of the images from closest approach have returned to Earth, the spacecraft will continue to send home data until the mid-2020s at a speed of only a few bits per minute. Once it has all returned to Earth, the team hopes to begin the hunt for the next target using telescopes back on Earth.

"The team has made a ton of progress on interpreting Arrokoth and what it means for solar system formation," Singer said. "It is still amazing to me that humanity now has pictures of one of the most primordial objects in our solar system."

And New Horizons's work may not be finished.

Alan Stern, the principal investigator of New Horizons, has said the mission team is still looking for other flyby targets that may arise in the Kuiper Belt.

"So as we look forward to the 2020s, our team is planning the next few years for New Horizons," he said in a blog post earlier this month, adding that the search won't start until this summer. "We don't know how many KBOs we will discover or whether any will be within our fuel supply to reach for a final close flyby, but that's what these searches, in 2020 and again in 2021, will reveal."

Follow Nola on Facebook and on Twitter at @NolaTRedd. Follow us on Twitter @Spacedotcom and on Facebook.

]]> https://www.space.com/new-horizons-arrokoth-ultima-thule-flyby-one-year-later.html U39Rsp4sGHMXWbQUVqw6WQ Wed, 01 Jan 2020 13:36:06 +0000 Wed, 01 Jan 2020 13:36:04 +0000 <![CDATA[ The Decade in Astronomy: These Space Discoveries Shaped the 2010s ]]> As the 2010s come to a close, it's time to revisit how some of the biggest space science stories shaped the decade.

From the rise of TESS to flybys of Pluto and Cassini's dramatic demise, the past ten years have produced some incredible science. Here are some of our favorite discoveries from the decade.

2010 saw cosmic chases and cosmic rays

The Deep Impact spacecraft proved to be an overachiever in 2010, chasing down a second comet after it had already observed one. After Deep Impact visited Comet Tempel 1 in 2005, NASA realized the spacecraft still had enough fuel to visit another comet as well. 2.9 billion extra miles (4.6 billion kilometers) later, it met up with Comet Hartley 2.

To researchers' surprise, the peanut-size comet was actually quite active, spewing cyanide-laced gas from its surface. This extra flyby made Deep Impact the first spacecraft to visit two comets in one mission.

Also in 2010, the sun began to wake up, with some extremely powerful solar flares! The sun goes through 11-year cycles of solar activity, and a particularly weak cycle came to an end in 2010. The result was that the sun began to exhibit powerful solar activity, which continued into 2011. These solar flares and eruptions can create dazzling aurora displays.

Scientists aren't quite sure why the sun seemed to be deviating from its typical intensity patterns but suspect it might be because of something similar to what the Earth experiences during El Nino climate patterns.

Timely arrivals in 2011

After a 6.5-year journey, NASA announced in 2011 that the Messenger spacecraft had safely entered into orbit around the planet Mercury. The completion of this tricky maneuver made Messenger the first artificial satellite to orbit Mercury. From this perch it collected data on the planet's geology, composition and thin atmosphere.

In another milestone arrival, NASA's Dawn spacecraft reached the asteroid belt between Mars and Jupiter to observe one of its largest rocks, Vesta. The asteroid was one of two stops for the spacecraft, which launched in 2007.

From some of Dawn's initial observations in 2011 scientists learned that this huge space rock had a battered surface, sporting mountain ranges and deep craters. The overall aim of the visit was to gather near-global visible and infrared images of Vesta in order to learn more about asteroid topology and composition.

We said goodbye to Voyager 1 in 2012

So long, Voyager 1! The spacecraft, which originally launched in 1977, finally passed beyond the influence of our sun and entered interstellar space in 2012. During its decades-long mission, the spacecraft sent back breathtaking photos of our solar system, including the famous "Pale Blue Dot" photograph it took in 1990. After it surpassed the Pioneer 1 spacecraft, Voyager 1 clocked the most distance traveled in space by any human-made object. (The spacecraft continues to relay data from its cosmic journey back to Earth even in 2019.)

Terrestrial explosions and discoveries in 2013

Originally dubbed the "comet of the century" due to its anticipated splendor, Comet ISON passed by the sun on November 28, 2013 (American Thanksgiving) and broke apart. Scientists had expected the comet to give off a dazzling light show as a result of what they'd believed to be a large nucleus, but the comet did little more than fade away.

The observations were a testament to just how hard comet detection and prediction can be. Upon further observation, scientists concluded that the comet's nucleus might have been much smaller than originally estimated. Nevertheless, the comet's slow approach still allowed scientists to study and learn more about comet behavior before it sizzled away.

Other drama came when it wasn't expected. A reminder of space's might, in February 2013 a 56-foot (17-meter) meteor exploded 930 miles above the city of Chelyabinsk in Russia, just east of Moscow. The explosion, which scientists say was equivalent to that of 470 kilotons of TNT, injured hundreds of people and damaged buildings across the area. Scientists say this impact may have been the most powerful terrestrial meteor impact since a 130-foot (40 m) object exploded over Siberia in 1908 and flattened 825 square miles (2,137 square km) of forest.

While not incredibly common, such impacts also aren't extremely rare either, and there's not much scientists can do about them. Instead, scientists continue to work on identifying and planning for larger asteroid impacts that could cause much more damage.

Also in 2013, scientists were able to identify evidence of cosmic rays on Earth. Because these rays are very difficult to detect, scientists instead relied on observing neutrinos left behind by the rays. Neutrinos themselves are also notoriously hard to detect because they almost never interact with matter, but in the case of these cosmic rays, the IceCube Observatory in Antarctica found that they did.

The neutrinos, named Bert and Ernie after the Sesame Street characters, significantly more energetic than those produced during an event detected in 1987, but still not powerful enough to provide scientists with definitive information about the origin of the rays. Astrophysicists concluded that top candidates might be a supernova, black hole or gamma ray burst.

Successful landings and new family photos in 2014

Touchdown on a comet! In a historic first, the European Space Agency (ESA) visited a comet's surface in 2014. The spacecraft, named the Philae lander, touched down and made brief observations. It was a challenging landing, since the comet was a very small, distant target and the Philae lander had to make a leap from the larger Rosetta spacecraft, in order to touch down.

Unfortunately, Philae bounced into a shadowy area on the comet where it was unable to use its solar panels. The lander soon slipped into hibernation mode. But before doing so, Philae was able to detect an icy surface on the comet and organic molecules like carbon.

Say cheese! In 2014, for the first time ever scientists were able to take an image of our universe's cosmic web. While galaxies seem like the epicenters of our universe, they're actually extremely small compared to all other matter in space. Using light from a quasar as a flashlight, scientists were able to get a better look at these cosmic dust tendrils.

This observation was fascinating unto itself, but also gave scientists a better model for how to track down elusive dark matter, because dark matter is believed to mirror the regular matter we are able to observe.

Important new 'hello's in 2015

Hello, Pluto! NASA's New Horizons spacecraft successfully flew past the icy dwarf planet in 2015. This is the first time we've been able to see Pluto and its moon Charon up close. Notably, scientists discovered that Pluto has an adorable heart on its surface and that it and Charon might actually be more geologically active than scientists first imagined. Where scientists expected to find a pock-marked surface, similar to that of our moon, they instead found a relatively young-looking surface. This smoothness led scientists to believe that the surface may have been reshaped more recently, perhaps by something like ice.

In September 2015 scientists confirmed that geysers observed on Saturn's moon Enceladus are evidence of a global ocean inside the moon, not an isolated lake. Scientists were able to determine this based on a slight wobble detected in Enceladus's orbit around Saturn. This discovery, as well as previous discoveries by Cassini of hydrothermal activity on the moon, make Enceladus a prime candidate for future, life-hunting missions in years to come.

2016 saw out-of-this-world discoveries

2016 was a historic year for physics. Scientists were able to observe for the first time ever evidence of gravitational waves, the wrinkling of space-time that occurs when objects collide. To do so, they relied on a massive laser interferometer called LIGO (Laser Interferometer Gravitational-Wave Observatory) with its twin detectors in Washington and Louisiana. Gravitational waves had been theorized by Einstein but had never been detected before.

Scientists detected two sets of gravitational waves in 2016, both triggered by the collisions of black holes millions of years prior that echoed across the universe. These discoveries would go on to win the Nobel Prize for physics in 2017.

In another strange discovery for the year, the Hubble Space Telescope spotted what appeared to be 125-mile-high (200 kilometers) geysers of water vapor erupting from the south pole of Jupiter's moon, Europa. Such a geyser was first spotted in 2012, but astronomers thought that observation was a fluke.

Scientists have known for a while now that an icy ocean lies beneath Europa's surface, but evidence of geyser eruptions means that it might be possible for probes to directly analyze Europa's water for signs of microbial life. NASA's Europa Clipper spacecraft, slated for launch next decade, will further investigate those possibilities.

Big discoveries and somber goodbyes in 2017

Aug. 17, 2017 was a life-changing day for astronomers. On that day, scientists observed the collision of two incredibly dense neutron stars, by detecting both gravitational waves and light created in the collision. While this was the fifth time scientists had observed gravitational waves, it was the first time they were able to observe such events through other measurements as well.

A massively international effort between observatories in Italy, Chile and a NASA space telescope allowed scientists to chase the gravitational-wave signal across the sky and locate the event using light observations. The team was able to confirm that the collision produced heavy elements like gold.

Just days later, people gathered at science museums and open spaces on Aug. 21 to observe a once-in-a-century event: the great American solar eclipse. The event crossed the country coast to coast, from Oregon to South Carolina, and ra 70-mile wide swath caught totality.

Farther from home, 2017 saw the demise of a beloved mission, Cassini. The spacecraft launched in 1997 to orbit and observe Saturn and its many moons — and boy, did it. During its 13-year dance with Saturn, the spacecraft discovered half a dozen moons, geysers on Enceladus and lakes on Titan, not to mention a treasure trove of beautiful images of the planet.

But all good things must eventually come to an end. After more than a decade of circling Saturn, Cassini was running out of fuel and its mission team decided to send it out with one last hurrah. The mission came to a fiery conclusion on Sept. 15, 2017, as Cassini purposefully dove into Saturn, burning up in its atmosphere like a meteor. The maneuver kept nearby moons safe from contamination and offered unprecedentedly close-up observations of the planet.

In October 2017 scientists detected the first known alien visitor passing through our solar system. A team of scientists modeled the path of the object, a space rock later named 'Oumuamua, and determined that it didn't originate in our solar system. While scientists have long theorized about how an alien object could come in contact with our solar system, this was the first observation of such an object.

The rise and fall of great missions in 2018

2018 was both an exhilarating and mournful year for space missions, ushering in exciting new prospects while also saying goodbye to some old favorites.

After nearly 15 years on the Martian surface, the Mars Opportunity rover finally lost contact with Earth on June 10, 2018, after a planet-wide dust storm caused the rover to retreat into low-power mode. Ater listening for months for a signal from the rover, the Opportunity team determined the mission complete at the end of January.

Opportunity and its twin rover, Spirit, landed on Mars in 2004 with a life-expectancy of 90 Martian days; both outlived that timeline with gusto. Spirit survived seven years on the Martian surface and Opportunity went on to last nearly 15, traveling a grand total of 26.5 miles (42.65 km) across the Red Planet and performing important geological analysis all the while. The conclusion of the mission touched the team involved with the mission and space enthusiasts alike.

The same year saw the end of another iconic mission, the exoplanet-hunting space telescope Kepler. The mission launched in March 2009 to see what kind of planets might be lurking beyond our solar system. While Kepler suffered an early failure in 2013 that effectively ended its initial mission, scientists were able to regain control of the telescope and transition it into a second phase, dubbed K2.

By the time that mission ended in November 2018, because the spacecraft didn't have enough fuel, Kepler had discovered a whopping 2,682 exoplanets between its two missions. And even now, there are still hundreds more exoplanet candidates identified by the mission but waiting to be confirmed by follow-up observations.

In a burst of good timing, Kepler's successor was already up and running after launching in April 2018. Like Kepler, the Transiting Exoplanet Survey Satellite (TESS) is designed to search for exoplanets. It is scanning both hemispheres of the sky during its first two years of operation, which continue into summer 2020. At the end of its first year, TESS had already found 28 confirmed exoplanets — several of which appear to be in the so-called habitable zone — and 993 potential planets.

With any luck, these swaths of exoplanet data collected by both TESS and Kepler will give the James Webb Space Telescope plenty to work with. The James Webb is scheduled to launch in 2021 and will, among other work, examine exoplanet atmospheres to learn more about these potentially habitable worlds.

2019

Scientists rang in the new year in 2019 with an incredibly distant flyby. New Horizons flew past a Kuiper Belt object dubbed 2014 MU69 just as the calendar turned over in North America. Now officially called Arrokoth, the object is a two-lobed spinning pancake in the cold, dark reaches of outer space. Now, scientists on the team are trying to determine whether the spacecraft has one more flyby left in it.

Other spacecraft made incredible space-rock visits this year as well. The Japanese spacecraft Hayabusa2 was orbiting an asteroid called Ryugu when the year began; over the course of 2019 it collected several samples, made an artificial crater on Ryugu's surface and turned back to Earth, where it will arrive late next year. A similar asteroid mission from NASA, OSIRIS-REx, spent all year studying its own space rock, Bennu, and strategizing how to collect samples from it.

In April, an international collaboration published the first ever image of a black hole, capturing imaginations around the world. The feat required turning all of Earth into a massive telescope of sorts, dubbed the Event Horizon Telescope, and processing truly mind-blowing amounts of data. The team released an image of the black hole at the center of a galaxy called M87; scientists have also been processing data about a similar structure at the heart of the Milky Way.

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]]> https://www.space.com/decade-in-astronomy-2010s-science-retrospective.html ThqbYrZAYX5NNjeGsjJTPV Fri, 27 Dec 2019 13:44:35 +0000 Wed, 30 Apr 2025 17:40:49 +0000