posted 07-14-2015 07:55 PM               

New Horizons spacecraft survives historic flyby of dwarf planet Pluto

NASA's New Horizons probe successfully flew past Pluto on Tuesday (July 14), becoming the first spacecraft in history to visit the orangish-red dwarf planet. The flyby crowned humanity's first reconnaissance of the solar system's nine major worlds.

The piano-sized probe made its closest approach of 7,750 miles (12,500 km) to Pluto at 7:49 a.m. EDT (1149 GMT), collecting imagery and science data as it soared past the small planet. About nine hours later, New Horizons turned its antenna dish away from the Pluto system and towards Earth so that it could "phone home" to confirm it survived the historic encounter.

That highly-anticipated call was received at 8:53 p.m. EDT (0053 GMT) to the visible and vocal elation of the mission operations and science team at Johns Hopkins University Applied Physics Laboratory in Maryland.

posted 07-15-2015 03:34 PM               

The Icy Mountains of Pluto

New close-up images of a region near Pluto's equator reveal a giant surprise: a range of youthful mountains rising as high as 11,000 feet (3,500 meters) above the surface of the icy body.

The mountains likely formed no more than 100 million years ago — mere youngsters relative to the 4.56-billion-year age of the solar system — and may still be in the process of building, says Jeff Moore of New Horizons' Geology, Geophysics and Imaging Team (GGI). That suggests the close-up region, which covers less than one percent of Pluto's surface, may still be geologically active today.

Moore and his colleagues base the youthful age estimate on the lack of craters in this scene. Like the rest of Pluto, this region would presumably have been pummeled by space debris for billions of years and would have once been heavily cratered — unless recent activity had given the region a facelift, erasing those pockmarks.

"This is one of the youngest surfaces we've ever seen in the solar system," says Moore.

Unlike the icy moons of giant planets, Pluto cannot be heated by gravitational interactions with a much larger planetary body. Some other process must be generating the mountainous landscape.

"This may cause us to rethink what powers geological activity on many other icy worlds," says GGI deputy team leader John Spencer of the Southwest Research Institute in Boulder, Colo.

The mountains are probably composed of Pluto's water-ice "bedrock."

Although methane and nitrogen ice covers much of the surface of Pluto, these materials are not strong enough to build the mountains. Instead, a stiffer material, most likely water-ice, created the peaks. "At Pluto's temperatures, water-ice behaves more like rock," said deputy GGI lead Bill McKinnon of Washington University, St. Louis.

The close-up image was taken about 1.5 hours before New Horizons closest approach to Pluto, when the craft was 478,000 miles (770,000 kilometers) from the surface of the planet. The image easily resolves structures smaller than a mile across.

posted 07-15-2015 03:35 PM               

Charon's Surprising, Youthful and Varied Terrain

Remarkable new details of Pluto's largest moon Charon are revealed in this image from New Horizons' Long Range Reconnaissance Imager (LORRI), taken late on July 13, 2015 from a distance of 289,000 miles (466,000 kilometers).

A swath of cliffs and troughs stretches about 600 miles (1,000 kilometers) from left to right, suggesting widespread fracturing of Charon's crust, likely a result of internal processes. At upper right, along the moon's curving edge, is a canyon estimated to be 4 to 6 miles (7 to 9 kilometers) deep.

Mission scientists are surprised by the apparent lack of craters on Charon. South of the moon's equator, at the bottom of this image, terrain is lit by the slanting rays of the sun, creating shadows that make it easier to distinguish topography. Even here, however, relatively few craters are visible, indicating a relatively young surface that has been reshaped by geologic activity.

In Charon's north polar region, a dark marking prominent in New Horizons' approach images is now seen to have a diffuse boundary, suggesting it is a thin deposit of dark material. Underlying it is a distinct, sharply bounded, angular feature; higher resolution images still to come are expected to shed more light on this enigmatic region.

The image has been compressed to reduce its file size for transmission to Earth. In high-contrast areas of the image, features as small as 3 miles (5 kilometers) across can be seen. Some lower-contrast detail is obscured by the compression of the image, which may make some areas appear smoother than they really are. The uncompressed version still resides in New Horizons' computer memory and is scheduled to be transmitted at a later date.

The image has been combined with color information obtained by New Horizons' Ralph instrument on July 13.

New Horizons traveled more than three billion miles over nine-and-a-half years to reach the Pluto system.

posted 07-15-2015 03:36 PM               

Pluto: The Ice Plot Thickens

The latest spectra from New Horizons Ralph instrument reveal an abundance of methane ice, but with striking differences from place to place across the frozen surface of Pluto.

"We just learned that in the north polar cap, methane ice is diluted in a thick, transparent slab of nitrogen ice resulting in strong absorption of infrared light," said New Horizons co-investigator Will Grundy, Lowell Observatory, Flagstaff, Arizona. In one of the visually dark equatorial patches, the methane ice has shallower infrared absorptions indicative of a very different texture. "The spectrum appears as if the ice is less diluted in nitrogen," Grundy speculated "or that it has a different texture in that area."

An Earthly example of different textures of a frozen substance: a fluffy bank of clean snow is bright white, but compacted polar ice looks blue. New Horizons' surface composition team, led by Grundy, has begun the intricate process of analyzing Ralph data to determine the detailed compositions of the distinct regions on Pluto.

This is the first detailed image of Pluto from the Linear Etalon Imaging Spectral Array, part of the Ralph instrument on New Horizons. The observations were made at three wavelengths of infrared light, which are invisible to the human eye. In this picture, blue corresponds to light of wavelengths 1.62 to 1.70 micrometers, a channel covering a medium-strong absorption band of methane ice, green (1.97 to 2.05 micrometers) represents a channel where methane ice does not absorb light, and red (2.30 to 2.33 micrometers) is a channel where the light is very heavily absorbed by methane ice. The two areas outlined on Pluto show where Ralph observations obtained the spectral traces at the right. Note that the methane absorptions (notable dips) in the spectrum from the northern region are much deeper than the dips in the spectrum from the dark patch. The Ralph data were obtained by New Horizons on July 12, 2015.

posted 07-15-2015 03:36 PM               

Hydra Emerges from the Shadows

Since its discovery in 2005, Pluto's moon Hydra has been known only as a fuzzy dot of uncertain shape, size, and reflectivity. Imaging obtained during New Horizons' historic transit of the Pluto-Charon system and transmitted to Earth early this morning has definitively resolved these fundamental properties of Pluto's outermost moon. Long Range Reconnaissance Imager (LORRI) observations revealed an irregularly shaped body characterized by significant brightness variations over the surface. With a resolution of 2 miles (3 kilometers) per pixel, the LORRI image shows the tiny potato-shaped moon measures 27 miles (43 kilometers) by 20 miles (33 kilometers).

Like that of Charon, Hydra's surface is probably covered with water ice, the most abundant ice in the universe. Observed within Hydra's bright regions is a darker circular structure with a diameter of approximately 6 miles (10 kilometers). Hydra's reflectivity (the percentage of incident light reflected from the surface) is intermediate between that of Pluto and Charon. "New Horizons has finally nailed the basic physical properties of Hydra," says Hal Weaver, New Horizons Project Scientist and LORRI science operations lead. "We're going to see Hydra even better in the images yet to come."

Hydra was approximately 400,000 miles away from New Horizons when the image was acquired.

posted 07-16-2015 03:50 PM               

This new image of an area on Pluto's largest moon Charon has a captivating feature — a depression with a peak in the middle, shown here in the upper left corner of the inset.

The image shows an area approximately 240 miles (390 kilometers) from top to bottom, including few visible craters. The image was taken at approximately 6:30 a.m. EDT on July 14, 2015, about 1.5 hours before closest approach to Pluto, from a range of 49,000 miles (79,000 kilometers).

NASA will hold a media briefing at 1 p.m. EDT Friday, July 17, to reveal new images of Pluto and discuss new science findings from Tuesday's historic flyby.

posted 07-17-2015 01:14 PM               

NASA's New Horizons Discovers Frozen Plains in the Heart of Pluto's 'Heart'

In the latest data from NASA's New Horizons spacecraft, a new close-up image of Pluto reveals a vast, craterless plain that appears to be no more than 100 million years old, and is possibly still being shaped by geologic processes. This frozen region is north of Pluto's icy mountains, in the center-left of the heart feature, informally named "Tombaugh Regio" (Tombaugh Region) after Clyde Tombaugh, who discovered Pluto in 1930.

Above: In the center left of Pluto's vast heart-shaped feature — informally named "Tombaugh Regio" — lies a vast, craterless plain that appears to be no more than 100 million years old, and is possibly still being shaped by geologic processes. This frozen region is north of Pluto's icy mountains and has been informally named Sputnik Planum (Sputnik Plain), after Earth's first artificial satellite. The surface appears to be divided into irregularly-shaped segments that are ringed by narrow troughs. Features that appear to be groups of mounds and fields of small pits are also visible. This image was acquired by the Long Range Reconnaissance Imager (LORRI) on July 14 from a distance of 48,000 miles (77,000 kilometers). Features as small as one-half mile (1 kilometer) across are visible. The blocky appearance of some features is due to compression of the image. (NASA/JHUAPL/SWRI)

"This terrain is not easy to explain," said Jeff Moore, leader of the New Horizons Geology, Geophysics and Imaging Team (GGI) at NASA's Ames Research Center in Moffett Field, California. "The discovery of vast, craterless, very young plains on Pluto exceeds all pre-flyby expectations."

This fascinating icy plains region — resembling frozen mud cracks on Earth — has been informally named "Sputnik Planum" (Sputnik Plain) after the Earth's first artificial satellite. It has a broken surface of irregularly-shaped segments, roughly 12 miles (20 kilometers) across, bordered by what appear to be shallow troughs. Some of these troughs have darker material within them, while others are traced by clumps of hills that appear to rise above the surrounding terrain. Elsewhere, the surface appears to be etched by fields of small pits that may have formed by a process called sublimation, in which ice turns directly from solid to gas, just as dry ice does on Earth.

Scientists have two working theories as to how these segments were formed. The irregular shapes may be the result of the contraction of surface materials, similar to what happens when mud dries. Alternatively, they may be a product of convection, similar to wax rising in a lava lamp. On Pluto, convection would occur within a surface layer of frozen carbon monoxide, methane and nitrogen, driven by the scant warmth of Pluto's interior.

Pluto's icy plains also display dark streaks that are a few miles long. These streaks appear to be aligned in the same direction and may have been produced by winds blowing across the frozen surface.

The Tuesday "heart of the heart" image was taken when New Horizons was 48,000 miles (77,000 kilometers) from Pluto, and shows features as small as one-half mile (1 kilometer) across. Mission scientists will learn more about these mysterious terrains from higher-resolution and stereo images that New Horizons will pull from its digital recorders and send back to Earth during the next year.

The New Horizons Atmospheres team observed Pluto's atmosphere as far as 1,000 miles (1,600 kilometers) above the surface, demonstrating that Pluto's nitrogen-rich atmosphere is quite extended. This is the first observation of Pluto's atmosphere at altitudes higher than 170 miles above the surface (270 kilometers).

The New Horizons Particles and Plasma team has discovered a region of cold, dense ionized gas tens of thousands of miles beyond Pluto — the planet's atmosphere being stripped away by the solar wind and lost to space.

"This is just a first tantalizing look at Pluto's plasma environment," said New Horizons co-investigator Fran Bagenal, University of Colorado, Boulder.

Above: This simulated flyover of Pluto's Norgay Montes (Norgay Mountains) and Sputnik Planum (Sputnik Plain) was created from New Horizons closest-approach images. Norgay Montes have been informally named for Tenzing Norgay, one of the first two humans to reach the summit of Mount Everest. Sputnik Planum is informally named for Earth's first artificial satellite. The images were acquired by the Long Range Reconnaissance Imager (LORRI) on July 14 from a distance of 48,000 miles (77,000 kilometers). Features as small as a half-mile (1 kilometer) across are visible.

"With the flyby in the rearview mirror, a decade-long journey to Pluto is over — but, the science payoff is only beginning," said Jim Green, director of Planetary Science at NASA Headquarters in Washington. "Data from New Horizons will continue to fuel discovery for years to come."

Alan Stern, New Horizons principal investigator from the Southwest Research Institute (SwRI), Boulder, Colorado, added, "We've only scratched the surface of our Pluto exploration, but it already seems clear to me that in the initial reconnaissance of the solar system, the best was saved for last."

posted 07-17-2015 01:14 PM               

Frozen Carbon Monoxide in Pluto's 'Heart'

Peering closely at the "heart of Pluto," in the western half of what mission scientists have informally named Tombaugh Regio (Tombaugh Region), New Horizons' Ralph instrument revealed evidence of carbon monoxide ice. The contours indicate that the concentration of frozen carbon monoxide increases towards the center of the "bull's eye." These data were acquired by the spacecraft on July 14 and transmitted to Earth on July 16.

posted 07-21-2015 10:49 AM               

New Horizons Captures Two of Pluto's Smaller Moons

Pluto has five known moons. In order of distance from Pluto they are: Charon, Styx, Nix, Kerberos, and Hydra.

While Pluto's largest moon Charon has grabbed most of the lunar spotlight, two of Pluto's smaller and lesser-known satellites are starting to come into focus via new images from the New Horizons spacecraft. Nix and Hydra – the second and third moons to be discovered – are approximately the same size, but their similarity ends there.

Above: Pluto's moon Nix (left), shown here in enhanced color as imaged by the New Horizons Ralph instrument, has a reddish spot that has attracted the interest of mission scientists. The data were obtained on the morning of July 14, 2015 and received on the ground on July 18. At the time the observations were taken New Horizons was about 102,000 miles (165,000 km) from Nix. The image shows features as small as 2 miles (3 kilometers) across on Nix, which is estimated to be 26 miles (42 kilometers) long and 22 miles (36 kilometers) wide.

Pluto's small, irregularly shaped moon Hydra (right) is revealed in this black and white image taken from New Horizons' LORRI instrument on July 14, 2015 from a distance of about 143,000 miles (231,000 kilometers). Features as small as 0.7 miles (1.2 kilometers) are visible on Hydra, which measures 34 miles (55 kilometers) in length. (NASA/JHUAPL/SWRI)

New Horizons' first color image of Pluto's moon Nix, in which colors have been enhanced, reveals an intriguing region on the jelly bean-shaped satellite, which is estimated to be 26 miles (42 kilometers) long and 22 miles (36 kilometers) wide.

Although the overall surface color of Nix is neutral grey in the image, the newfound region has a distinct red tint. Hints of a bull's-eye pattern lead scientists to speculate that the reddish region is a crater. "Additional compositional data has already been taken of Nix, but is not yet downlinked. It will tell us why this region is redder than its surroundings," said mission scientist Carly Howett, Southwest Research Institute, Boulder, Colorado. She added, "This observation is so tantalizing, I'm finding it hard to be patient for more Nix data to be downlinked."

Meanwhile, the sharpest image yet received from New Horizons of Pluto's satellite Hydra shows that its irregular shape resembles the state of Michigan. The new image was made by the Long Range Reconnaissance Imager (LORRI) on July 14, 2015 from a distance of 143,000 miles (231,000 kilometers), and shows features as small as 0.7 miles (1.2 kilometers) across. There appear to be at least two large craters, one of which is mostly in shadow. The upper portion looks darker than the rest of Hydra, suggesting a possible difference in surface composition. From this image, mission scientists have estimated that Hydra is 34 miles (55 kilometers) long and 25 miles (40 kilometers) wide. Commented mission science collaborator Ted Stryk of Roane State Community College in Tennessee, "Before last week, Hydra was just a faint point of light, so it's a surreal experience to see it become an actual place, as we see its shape and spot recognizable features on its surface for the first time."

Images of Pluto's most recently discovered moons, Styx and Kerberos, are expected to be transmitted to Earth no later than mid-October.

Nix and Hydra were both discovered in 2005 using Hubble Space Telescope data by a research team led by New Horizons project scientist Hal Weaver, Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland. New Horizons' findings on the surface characteristics and other properties of Nix and Hydra will help scientists understand the origins and subsequent history of Pluto and its moons.

posted 07-21-2015 03:15 PM               

NASA's New Horizons Finds Second Mountain Range in Pluto's 'Heart'

A newly discovered mountain range lies near the southwestern margin of Pluto's Tombaugh Regio (Tombaugh Region), situated between bright, icy plains and dark, heavily-cratered terrain. This image was acquired by New Horizons' Long Range Reconnaissance Imager (LORRI) on July 14, 2015 from a distance of 48,000 miles (77,000 kilometers) and sent back to Earth on July 20. Features as small as a half-mile (1 kilometer) across are visible.

Above: This image was acquired by New Horizons' LORRI (Long Range Reconnaissance Imager) on July 14, 2015 from a distance of 48,000 miles (77,000 kilometers) and received on Earth on July 20. Features as small as a half-mile (1 kilometer) across are visible. (NASA/JHUAPL/SWRI)

Pluto's icy mountains have company. NASA's New Horizons mission has discovered a new, apparently less lofty mountain range on the lower-left edge of Pluto's best known feature, the bright, heart-shaped region named Tombaugh Regio (Tombaugh Region).

These newly-discovered frozen peaks are estimated to be one-half mile to one mile (1-1.5 kilometers) high, about the same height as the United States' Appalachian Mountains. The Norgay Montes (Norgay Mountains) discovered by New Horizons on July 15 more closely approximate the height of the taller Rocky Mountains.

The new range is just west of the region within Pluto's heart called Sputnik Planum (Sputnik Plain). The peaks lie some 68 miles (110 kilometers) northwest of Norgay Montes.

This newest image further illustrates the remarkably well-defined topography along the western edge of Tombaugh Regio.

"There is a pronounced difference in texture between the younger, frozen plains to the east and the dark, heavily-cratered terrain to the west," said Jeff Moore, leader of the New Horizons Geology, Geophysics and Imaging Team (GGI) at NASA's Ames Research Center in Moffett Field, California. "There's a complex interaction going on between the bright and the dark materials that we're still trying to understand."

While Sputnik Planum is believed to be relatively young in geological terms – perhaps less than 100 million years old - the darker region probably dates back billions of years. Moore notes that the bright, sediment-like material appears to be filling in old craters (for example, the bright circular feature to the lower left of center).

This image was acquired by the Long Range Reconnaissance Imager (LORRI) on July 14 from a distance of 48,000 miles (77,000 kilometers) and sent back to Earth on July 20. Features as small as a half-mile (1 kilometer) across are visible. The names of features on Pluto have all been given on an informal basis by the New Horizons team.

posted 07-24-2015 02:30 PM               

NASA's New Horizons Team Finds Haze, Flowing Ice on Pluto

Flowing ice and a surprising extended haze are among the newest discoveries from NASA's New Horizons mission, which reveal distant Pluto to be an icy world of wonders.

"We knew that a mission to Pluto would bring some surprises, and now — 10 days after closest approach — we can say that our expectation has been more than surpassed," said John Grunsfeld, NASA's associate administrator for the Science Mission Directorate. "With flowing ices, exotic surface chemistry, mountain ranges, and vast haze, Pluto is showing a diversity of planetary geology that is truly thrilling."

Above: Pluto sends a breathtaking farewell to New Horizons. Backlit by the sun, Pluto's atmosphere rings its silhouette like a luminous halo in this image taken by NASA's New Horizons spacecraft around midnight EDT on July 15. This global portrait of the atmosphere was captured when the spacecraft was about 1.25 million miles (2 million kilometers) from Pluto and shows structures as small as 12 miles across. The image, delivered to Earth on July 23, is displayed with north at the top of the frame. (NASA/JHUAPL/SwRI)

Just seven hours after closest approach, New Horizons aimed its Long Range Reconnaissance Imager (LORRI) back at Pluto, capturing sunlight streaming through the atmosphere and revealing hazes as high as 80 miles (130 kilometers) above Pluto's surface. A preliminary analysis of the image shows two distinct layers of haze — one about 50 miles (80 kilometers) above the surface and the other at an altitude of about 30 miles (50 kilometers).

"My jaw was on the ground when I saw this first image of an alien atmosphere in the Kuiper Belt," said Alan Stern, principal investigator for New Horizons at the Southwest Research Institute (SwRI) in Boulder, Colorado. "It reminds us that exploration brings us more than just incredible discoveries — it brings incredible beauty."

Studying Pluto's atmosphere provides clues as to what's happening below.

"The hazes detected in this image are a key element in creating the complex hydrocarbon compounds that give Pluto's surface its reddish hue," said Michael Summers, New Horizons co-investigator at George Mason University in Fairfax, Virginia.

Models suggest the hazes form when ultraviolet sunlight breaks up methane gas particles — a simple hydrocarbon in Pluto's atmosphere. The breakdown of methane triggers the buildup of more complex hydrocarbon gases, such as ethylene and acetylene, which also were discovered in Pluto's atmosphere by New Horizons. As these hydrocarbons fall to the lower, colder parts of the atmosphere, they condense into ice particles that create the hazes. Ultraviolent sunlight chemically converts hazes into tholins, the dark hydrocarbons that color Pluto's surface.

Scientists previously had calculated temperatures would be too warm for hazes to form at altitudes higher than 20 miles (30 kilometers) above Pluto's surface.

"We're going to need some new ideas to figure out what's going on," said Summers.

The New Horizons mission also found in LORRI images evidence of exotic ices flowing across Pluto's surface and revealing signs of recent geologic activity, something scientists hoped to find but didn't expect.

The new images show fascinating details within the Texas-sized plain, informally named Sputnik Planum, which lies within the western half of Pluto's heart-shaped feature, known as Tombaugh Regio. There, a sheet of ice clearly appears to have flowed — and may still be flowing — in a manner similar to glaciers on Earth.

"We've only seen surfaces like this on active worlds like Earth and Mars," said mission co-investigator John Spencer of SwRI. "I'm really smiling."

Additionally, new compositional data from New Horizons' Ralph instrument indicate the center of Sputnik Planum is rich in nitrogen, carbon monoxide, and methane ices.

"At Pluto's temperatures of minus-390 degrees Fahrenheit, these ices can flow like a glacier," said Bill McKinnon, deputy leader of the New Horizons Geology, Geophysics and Imaging team at Washington University in St. Louis. "In the southernmost region of the heart, adjacent to the dark equatorial region, it appears that ancient, heavily-cratered terrain has been invaded by much newer icy deposits."

View a simulated flyover using New Horizons' close-approach images of Sputnik Planum and Pluto's newly-discovered mountain range, informally named Hillary Montes, in the video below:

The New Horizons mission will continue to send data stored in its onboard recorders back to Earth through late 2016. The spacecraft currently is 7.6 million miles (12.2 million kilometers) beyond Pluto, healthy and flying deeper into the Kuiper Belt.

posted 08-28-2015 04:08 PM               

NASA's New Horizons Team Selects Potential Kuiper Belt Flyby Target

NASA has selected the potential next destination for the New Horizons mission to visit after its historic July 14 flyby of the Pluto system. The destination is a small Kuiper Belt object (KBO) known as 2014 MU69 that orbits nearly a billion miles beyond Pluto.

This remote KBO was one of two identified as potential destinations and the one recommended to NASA by the New Horizons team. Although NASA has selected 2014 MU69 as the target, as part of its normal review process the agency will conduct a detailed assessment before officially approving the mission extension to conduct additional science.

Above: Artist's impression of NASA's New Horizons spacecraft encountering a Pluto-like object in the distant Kuiper Belt. Credit: NASA/JHUAPL/SwRI/Alex Parker

"Even as the New Horizon's spacecraft speeds away from Pluto out into the Kuiper Belt, and the data from the exciting encounter with this new world is being streamed back to Earth, we are looking outward to the next destination for this intrepid explorer," said John Grunsfeld, astronaut and chief of the NASA Science Mission Directorate at the agency headquarters in Washington. "While discussions whether to approve this extended mission will take place in the larger context of the planetary science portfolio, we expect it to be much less expensive than the prime mission while still providing new and exciting science."

Like all NASA missions that have finished their main objective but seek to do more exploration, the New Horizons team must write a proposal to the agency to fund a KBO mission. That proposal – due in 2016 – will be evaluated by an independent team of experts before NASA can decide about the go-ahead.

Early target selection was important; the team needs to direct New Horizons toward the object this year in order to perform any extended mission with healthy fuel margins. New Horizons will perform a series of four maneuvers in late October and early November to set its course toward 2014 MU69 – nicknamed "PT1" (for "Potential Target 1") – which it expects to reach on January 1, 2019. Any delays from those dates would cost precious fuel and add mission risk.

"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," said New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute (SwRI) in Boulder, Colorado. "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."

New Horizons was originally designed to fly beyond the Pluto system and explore additional Kuiper Belt objects. The spacecraft carries extra hydrazine fuel for a KBO flyby; its communications system is designed to work from far beyond Pluto; its power system is designed to operate for many more years; and its scientific instruments were designed to operate in light levels much lower than it will experience during the 2014 MU69 flyby."

The 2003 National Academy of Sciences' Planetary Decadal Survey ("New Frontiers in the Solar System") strongly recommended that the first mission to the Kuiper Belt include flybys of Pluto and small KBOs, in order to sample the diversity of objects in that previously unexplored region of the solar system. The identification of PT1, which is in a completely different class of KBO than Pluto, potentially allows New Horizons to satisfy those goals.

But finding a suitable KBO flyby target was no easy task. Starting a search in 2011 using some of the largest ground-based telescopes on Earth, the New Horizons team found several dozen KBOs, but none were reachable within the fuel supply available aboard the spacecraft.

The powerful Hubble Space Telescope came to the rescue in summer 2014, discovering five objects, since narrowed to two, within New Horizons' flight path. Scientists estimate that PT1 is just under 30 miles (about 45 kilometers) across; that's more than 10 times larger and 1,000 times more massive than typical comets, like the one the Rosetta mission is now orbiting, but only about 0.5 to 1 percent of the size (and about 1/10,000th the mass) of Pluto. As such, PT1 is thought to be like the building blocks of Kuiper Belt planets such as Pluto.

Above: Path of NASA's New Horizons spacecraft toward its next potential target, the Kuiper Belt object 2014 MU69, nicknamed "PT1" (for "Potential Target 1") by the New Horizons team. NASA must approve any New Horizons extended mission to explore a KBO. Credit: NASA/JHUAPL/SwRI/Alex Parker

Unlike asteroids, KBOs have been heated only slightly by the Sun, and are thought to represent a well preserved, deep-freeze sample of what the outer solar system was like following its birth 4.6 billion years ago.

"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," said New Horizons science team member John Spencer, also of SwRI. "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."

The New Horizons spacecraft – currently 3 billion miles [4.9 billion kilometers] from Earth – is just starting to transmit the bulk of the images and other data, stored on its digital recorders, from its historic July encounter with the Pluto system. The spacecraft is healthy and operating normally.

posted 09-10-2015 01:55 PM               

New Pluto Images from NASA's New Horizons: It's Complicated

New close-up images of Pluto from NASA's New Horizons spacecraft reveal a bewildering variety of surface features that have scientists reeling because of their range and complexity.

Above: This synthetic perspective view of Pluto, based on the latest high-resolution images to be downlinked from NASA's New Horizons spacecraft, shows what you would see if you were approximately 1,100 miles (1,800 kilometers) above Pluto's equatorial area, looking northeast over the dark, cratered, informally named Cthulhu Regio toward the bright, smooth, expanse of icy plains informally called Sputnik Planum. The entire expanse of terrain seen in this image is 1,100 miles (1,800 kilometers) across. The images were taken as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers).

"Pluto is showing us a diversity of landforms and complexity of processes that rival anything we've seen in the solar system," said New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute (SwRI), Boulder, Colorado. "If an artist had painted this Pluto before our flyby, I probably would have called it over the top — but that's what is actually there."

New Horizons began its yearlong download of new images and other data over the Labor Day weekend. Images downlinked in the past few days have more than doubled the amount of Pluto's surface seen at resolutions as good as 400 meters (440 yards) per pixel. They reveal new features as diverse as possible dunes, nitrogen ice flows that apparently oozed out of mountainous regions onto plains, and even networks of valleys that may have been carved by material flowing over Pluto's surface. They also show large regions that display chaotically jumbled mountains reminiscent of disrupted terrains on Jupiter's icy moon Europa.

"The surface of Pluto is every bit as complex as that of Mars," said Jeff Moore, leader of the New Horizons Geology, Geophysics and Imaging (GGI) team at NASA's Ames Research Center in Moffett Field, California. "The randomly jumbled mountains might be huge blocks of hard water ice floating within a vast, denser, softer deposit of frozen nitrogen within the region informally named Sputnik Planum."

Above: In the center of this 300-mile (470-kilometer) wide image of Pluto from NASA's New Horizons spacecraft is a large region of jumbled, broken terrain on the northwestern edge of the vast, icy plain informally called Sputnik Planum, to the right. The smallest visible features are 0.5 miles (0.8 kilometers) in size. This image was taken as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers).

New images also show the most heavily cratered — and thus oldest — terrain yet seen by New Horizons on Pluto next to the youngest, most crater-free icy plains. There might even be a field of dark wind-blown dunes, among other possibilities.

"Seeing dunes on Pluto — if that is what they are — would be completely wild, because Pluto's atmosphere today is so thin," said William B. McKinnon, a GGI deputy lead from Washington University, St. Louis. "Either Pluto had a thicker atmosphere in the past, or some process we haven't figured out is at work. It's a head-scratcher."

Discoveries being made from the new imagery are not limited to Pluto's surface. Better images of Pluto's moons Charon, Nix, and Hydra will be released Friday at the raw images site for New Horizons' Long Range Reconnaissance Imager (LORRI), revealing that each moon is unique and that big moon Charon's geological past was a tortured one.

Images returned in the past days have also revealed that Pluto's global atmospheric haze has many more layers than scientists realized, and that the haze actually creates a twilight effect that softly illuminates nightside terrain near sunset, making them visible to the cameras aboard New Horizons.

Above: This image of Pluto from NASA's New Horizons spacecraft, processed in two different ways, shows how Pluto's bright, high-altitude atmospheric haze produces a twilight that softly illuminates the surface before sunrise and after sunset, allowing the sensitive cameras on New Horizons to see details in nighttime regions that would otherwise be invisible. The right-hand version of the image has been greatly brightened to bring out faint details of rugged haze-lit topography beyond Pluto's terminator, which is the line separating day and night. The image was taken as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers).

"This bonus twilight view is a wonderful gift that Pluto has handed to us," said John Spencer, a GGI deputy lead from SwRI. "Now we can study geology in terrain that we never expected to see."

The New Horizons spacecraft is now more than 3 billion miles (about 5 billion kilometers) from Earth, and more than 43 million miles (69 million kilometers) beyond Pluto. The spacecraft is healthy and all systems are operating normally.

posted 09-17-2015 11:56 AM               

Pluto 'Wows' in Spectacular New Backlit Panorama

The latest images from NASA's New Horizons spacecraft have scientists stunned – not only for their breathtaking views of Pluto's majestic icy mountains, streams of frozen nitrogen and haunting low-lying hazes, but also for their strangely familiar, arctic look.

Above: Just 15 minutes after its closest approach to Pluto on July 14, 2015, NASA's New Horizons spacecraft looked back toward the sun and captured this near-sunset view of the rugged, icy mountains and flat ice plains extending to Pluto's horizon.

The smooth expanse of the informally named icy plain Sputnik Planum (right) is flanked to the west (left) by rugged mountains up to 11,000 feet (3,500 meters) high, including the informally named Norgay Montes in the foreground and Hillary Montes on the skyline. To the right, east of Sputnik, rougher terrain is cut by apparent glaciers.

The backlighting highlights over a dozen layers of haze in Pluto's tenuous but distended atmosphere. The image was taken from a distance of 11,000 miles (18,000 kilometers) to Pluto; the scene is 780 miles (1,250 kilometers) wide. (NASA/JHUAPL/SwRI)

This new view of Pluto's crescent — taken by New Horizons' wide-angle Ralph/Multispectral Visual Imaging Camera (MVIC) on July 14 and downlinked to Earth on Sept. 13 — offers an oblique look across Plutonian landscapes with dramatic backlighting from the sun. It spectacularly highlights Pluto's varied terrains and extended atmosphere. The scene measures 780 miles (1,250 kilometers) across.

"This image really makes you feel you are there, at Pluto, surveying the landscape for yourself," said New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute, Boulder, Colorado. "But this image is also a scientific bonanza, revealing new details about Pluto's atmosphere, mountains, glaciers and plains."

Owing to its favorable backlighting and high resolution, this MVIC image also reveals new details of hazes throughout Pluto's tenuous but extended nitrogen atmosphere. The image shows more than a dozen thin haze layers extending from near the ground to at least 60 miles (100 kilometers) above the surface. In addition, the image reveals at least one bank of fog-like, low-lying haze illuminated by the setting sun against Pluto's dark side, raked by shadows from nearby mountains.

"In addition to being visually stunning, these low-lying hazes hint at the weather changing from day to day on Pluto, just like it does here on Earth," said Will Grundy, lead of the New Horizons Composition team from Lowell Observatory, Flagstaff, Arizona.

Combined with other recently downloaded pictures, this new image also provides evidence for a remarkably Earth-like "hydrological" cycle on Pluto — but involving soft and exotic ices, including nitrogen, rather than water ice.

Bright areas east of the vast icy plain informally named Sputnik Planum appear to have been blanketed by these ices, which may have evaporated from the surface of Sputnik and then been redeposited to the east. The new Ralph imager panorama also reveals glaciers flowing back into Sputnik Planum from this blanketed region; these features are similar to the frozen streams on the margins of ice caps on Greenland and Antarctica.

"We did not expect to find hints of a nitrogen-based glacial cycle on Pluto operating in the frigid conditions of the outer solar system," said Alan Howard, a member of the mission's Geology, Geophysics and Imaging team from the University of Virginia, Charlottesville. "Driven by dim sunlight, this would be directly comparable to the hydrological cycle that feeds ice caps on Earth, where water is evaporated from the oceans, falls as snow, and returns to the seas through glacial flow."

"Pluto is surprisingly Earth-like in this regard," added Stern, "and no one predicted it."

Above: In this small section of the larger crescent image of Pluto, taken by NASA's New Horizons just 15 minutes after the spacecraft's closest approach on July 14, 2015, the setting sun illuminates a fog or near-surface haze, which is cut by the parallel shadows of many local hills and small mountains. The image was taken from a distance of 11,000 miles (18,000 kilometers), and the width of the image is 115 miles (185 kilometers). (NASA/JHUAPL/SwRI)

posted 09-17-2015 11:57 AM               

Above: Sputnik Planum is the informal name of the smooth, light-bulb shaped region on the left of this composite of several New Horizons images of Pluto. The brilliantly white upland region to the right may be coated by nitrogen ice that has been transported through the atmosphere from the surface of Sputnik Planum, and deposited on these uplands. The box shows the location of the glacier detail images below.

Above: Ice (probably frozen nitrogen) that appears to have accumulated on the uplands on the right side of this 390-mile (630-kilometer) wide image is draining from Pluto's mountains onto the informally named Sputnik Planum through the 2- to 5-mile (3- to 8- kilometer) wide valleys indicated by the red arrows. The flow front of the ice moving into Sputnik Planum is outlined by the blue arrows. The origin of the ridges and pits on the right side of the image remains uncertain.

Above: This image covers the same region as the image above, but is re-projected from the oblique, backlit view shown in the new crescent image of Pluto. The backlighting highlights the intricate flow lines on the glaciers. The flow front of the ice moving into the informally named Sputnik Planum is outlined by the blue arrows. The origin of the ridges and pits on the right side of the image remains uncertain. This image is 390 miles (630 kilometers) across.

posted 09-24-2015 03:30 PM               

Perplexing Pluto: New 'Snakeskin' Image and More from New Horizons

The newest high-resolution images of Pluto from NASA's New Horizons are both dazzling and mystifying, revealing a multitude of previously unseen topographic and compositional details. The image below — showing an area near the line that separates day from night — captures a vast rippling landscape of strange, aligned linear ridges that has astonished New Horizons team members.

Above: In this extended color image of Pluto taken by NASA's New Horizons spacecraft, rounded and bizarrely textured mountains, informally named the Tartarus Dorsa, rise up along Pluto's day-night terminator and show intricate but puzzling patterns of blue-gray ridges and reddish material in between. This view, roughly 330 miles (530 kilometers) across, combines blue, red and infrared images taken by the Ralph/Multispectral Visual Imaging Camera (MVIC) on July 14, 2015, and resolves details and colors on scales as small as 0.8 miles (1.3 kilometers). Credits: NASA/JHUAPL/SWRI

"It's a unique and perplexing landscape stretching over hundreds of miles," said William McKinnon, New Horizons Geology, Geophysics and Imaging (GGI) team deputy lead from Washington University in St. Louis. "It looks more like tree bark or dragon scales than geology. This'll really take time to figure out; maybe it's some combination of internal tectonic forces and ice sublimation driven by Pluto's faint sunlight."

The "snakeskin" image of Pluto's surface is just one tantalizing piece of data New Horizons sent back in recent days. The spacecraft also captured the highest-resolution color view yet of Pluto, as well as detailed spectral maps and other high-resolution images.

The new "extended color" view of Pluto — taken by New Horizons' wide-angle Ralph/Multispectral Visual Imaging Camera (MVIC) on July 14 and downlinked to Earth on Sept. 19 — shows the extraordinarily rich color palette of Pluto.

"We used MVIC's infrared channel to extend our spectral view of Pluto," said John Spencer, a GGI deputy lead from Southwest Research Institute (SwRI) in Boulder, Colorado. "Pluto's surface colors were enhanced in this view to reveal subtle details in a rainbow of pale blues, yellows, oranges, and deep reds. Many landforms have their own distinct colors, telling a wonderfully complex geological and climatological story that we have only just begun to decode."

Above: This cylindrical projection map of Pluto, in enhanced, extended color, is the most detailed color map of Pluto ever made. It uses recently returned color imagery from the New Horizons Ralph camera, which is draped onto a base map of images from the NASA's spacecraft's Long Range Reconnaissance Imager (LORRI). The map can be zoomed in to reveal exquisite detail with high scientific value. Color variations have been enhanced to bring out subtle differences. Colors used in this map are the blue, red, and near-infrared filter channels of the Ralph instrument. Credits: NASA/JHUAPL/SWRI

Additionally, a high-resolution swath across Pluto taken by New Horizons' narrow-angle Long Range Reconnaissance Imager (LORRI) on July 14, and downlinked on Sept. 20, homes in on details of Pluto's geology. These images — the highest-resolution yet available of Pluto — reveal features that resemble dunes, the older shoreline of a shrinking glacial ice lake, and fractured, angular water ice mountains with sheer cliffs. Color details have been added using MVIC's global map shown above.

This closer look at the smooth, bright surface of the informally named Sputnik Planum shows that it is actually pockmarked by dense patterns of pits, low ridges and scalloped terrain. Dunes of bright volatile ice particles are a possible explanation, mission scientists say, but the ices of Sputnik may be especially susceptible to sublimation and formation of such corrugated ground.

Beyond the new images, new compositional information comes from a just-obtained map of methane ice across part of Pluto's surface that reveals striking contrasts: Sputnik Planum has abundant methane, while the region informally named Cthulhu Regio shows none, aside from a few isolated ridges and crater rims. Mountains along the west flank of Sputnik lack methane as well.

The distribution of methane across the surface is anything but simple, with higher concentrations on bright plains and crater rims, but usually none in the centers of craters or darker regions. Outside of Sputnik Planum, methane ice appears to favor brighter areas, but scientists aren't sure if that's because methane is more likely to condense there or that its condensation brightens those regions.

"It's like the classic chicken-or-egg problem," said Will Grundy, New Horizons surface composition team lead from Lowell Observatory in Flagstaff, Arizona. "We're unsure why this is so, but the cool thing is that New Horizons has the ability to make exquisite compositional maps across the surface of Pluto, and that'll be crucial to resolving how enigmatic Pluto works."

"With these just-downlinked images and maps, we've turned a new page in the study of Pluto beginning to reveal the planet at high resolution in both color and composition," added New Horizons Principal Investigator Alan Stern, of SwRI. "I wish Pluto's discoverer Clyde Tombaugh had lived to see this day."

posted 09-24-2015 03:31 PM               

Above: High-resolution images of Pluto taken by NASA's New Horizons spacecraft just before closest approach on July 14, 2015, reveal features as small as 270 yards (250 meters) across, from craters to faulted mountain blocks, to the textured surface of the vast basin informally called Sputnik Planum. Enhanced color has been added from the global color image. This image is about 330 miles (530 kilometers) across. For optimal viewing, zoom in on the image on a larger screen. Credits: NASA/JHUAPL/SWRI

Above: High-resolution images of Pluto taken by NASA's New Horizons spacecraft just before closest approach on July 14, 2015, are the sharpest images to date of Pluto's varied terrain — revealing details down to scales of 270 meters. In this 75-mile (120-kilometer) section of the taken from the larger, high-resolution mosaic above, the textured surface of the plain surrounds two isolated ice mountains.

The Ralph/LEISA infrared spectrometer on NASA's New Horizons spacecraft mapped compositions across Pluto's surface as it flew by on July 14. On the left, a map of methane ice abundance shows striking regional differences, with stronger methane absorption indicated by the brighter purple colors here, and lower abundances shown in black. Data have only been received so far for the left half of Pluto's disk. At right, the methane map is merged with higher-resolution images from the spacecraft's Long Range Reconnaissance Imager (LORRI).

posted 10-01-2015 12:10 PM               

Pluto's Big Moon Charon Reveals a Colorful and Violent History

NASA's New Horizons spacecraft has returned the best color and the highest resolution images yet of Pluto's largest moon, Charon – and these pictures show a surprisingly complex and violent history.

Above: Charon in Enhanced Color NASA's New Horizons captured this high-resolution enhanced color view of Charon just before closest approach on July 14, 2015. The image combines blue, red and infrared images taken by the spacecraft's Ralph/Multispectral Visual Imaging Camera (MVIC); the colors are processed to best highlight the variation of surface properties across Charon.

Charon's color palette is not as diverse as Pluto's; most striking is the reddish north (top) polar region, informally named Mordor Macula. Charon is 754 miles (1,214 kilometers) across; this image resolves details as small as 1.8 miles (2.9 kilometers). (NASA/JHUAPL/SwRI)

At half the diameter of Pluto, Charon is the largest satellite relative to its planet in the solar system. Many New Horizons scientists expected Charon to be a monotonous, crater-battered world; instead, they're finding a landscape covered with mountains, canyons, landslides, surface-color variations and more.

"We thought the probability of seeing such interesting features on this satellite of a world at the far edge of our solar system was low," said Ross Beyer, an affiliate of the New Horizons Geology, Geophysics and Imaging (GGI) team from the SETI Institute and NASA Ames Research Center in Mountain View, California, "but I couldn't be more delighted with what we see."

Above: High-resolution images of Charon were taken by the Long Range Reconnaissance Imager on NASA's New Horizons spacecraft, shortly before closest approach on July 14, 2015, and overlaid with enhanced color from the Ralph/Multispectral Visual Imaging Camera (MVIC). Charon's cratered uplands at the top are broken by series of canyons, and replaced on the bottom by the rolling plains of the informally named Vulcan Planum. The scene covers Charon's width of 754 miles (1,214 kilometers) and resolves details as small as 0.5 miles (0.8 kilometers). (NASA/JHUAPL/SwRI)

High-resolution images of the Pluto-facing hemisphere of Charon, taken by New Horizons as the spacecraft sped through the Pluto system on July 14 and transmitted to Earth on Sept. 21, reveal details of a belt of fractures and canyons just north of the moon's equator. This great canyon system stretches more than 1,000 miles (1,600 kilometers) across the entire face of Charon and likely around onto Charon's far side. Four times as long as the Grand Canyon, and twice as deep in places, these faults and canyons indicate a titanic geological upheaval in Charon's past.

"It looks like the entire crust of Charon has been split open," said John Spencer, deputy lead for GGI at the Southwest Research Institute in Boulder, Colorado. "With respect to its size relative to Charon, this feature is much like the vast Valles Marineris canyon system on Mars."

Above: This composite of enhanced color images of Pluto (lower right) and Charon (upper left), was taken by NASA's New Horizons spacecraft as it passed through the Pluto system on July 14, 2015. This image highlights the striking differences between Pluto and Charon.

The team has also discovered that the plains south of the Charon's canyon — informally referred to as Vulcan Planum — have fewer large craters than the regions to the north, indicating that they are noticeably younger. The smoothness of the plains, as well as their grooves and faint ridges, are clear signs of wide-scale resurfacing.

One possibility for the smooth surface is a kind of cold volcanic activity, called cryovolcanism. "The team is discussing the possibility that an internal water ocean could have frozen long ago, and the resulting volume change could have led to Charon cracking open, allowing water-based lavas to reach the surface at that time," said Paul Schenk, a New Horizons team member from the Lunar and Planetary Institute in Houston.

Even higher-resolution Charon images and composition data are still to come as New Horizons transmits data, stored on its digital recorders, over the next year — and as that happens, "I predict Charon's story will become even more amazing!" said mission Project Scientist Hal Weaver, of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.

The New Horizons spacecraft is currently 3.1 billion miles (5 billion kilometers) from Earth, with all systems healthy and operating normally.

posted 10-08-2015 10:35 AM               

New Horizons Finds Blue Skies and Water Ice on Pluto

The first color images of Pluto's atmospheric hazes, returned by NASA's New Horizons spacecraft last week, reveal that the hazes are blue.

"Who would have expected a blue sky in the Kuiper Belt? It's gorgeous," said Alan Stern, New Horizons principal investigator from Southwest Research Institute (SwRI), Boulder, Colorado.

Above: Pluto's haze layer shows its blue color in this picture taken by the New Horizons Ralph/Multispectral Visible Imaging Camera (MVIC). The high-altitude haze is thought to be similar in nature to that seen at Saturn's moon Titan. The source of both hazes likely involves sunlight-initiated chemical reactions of nitrogen and methane, leading to relatively small, soot-like particles (called tholins) that grow as they settle toward the surface.

This image was generated by software that combines information from blue, red and near-infrared images to replicate the color a human eye would perceive as closely as possible. (NASA/JHUAPL/SwRI)

The haze particles themselves are likely gray or red, but the way they scatter blue light has gotten the attention of the New Horizons science team. "That striking blue tint tells us about the size and composition of the haze particles," said science team researcher Carly Howett, also of SwRI. "A blue sky often results from scattering of sunlight by very small particles. On Earth, those particles are very tiny nitrogen molecules. On Pluto they appear to be larger — but still relatively small — soot-like particles we call tholins."

Scientists believe the tholin particles form high in the atmosphere, where ultraviolet sunlight breaks apart and ionizes nitrogen and methane molecules and allows them to react with one another to form more and more complex negatively and positively charged ions. When they recombine, they form very complex macromolecules, a process first found to occur in the upper atmosphere of Saturn's moon Titan. The more complex molecules continue to combine and grow until they become small particles; volatile gases condense and coat their surfaces with ice frost before they have time to fall through the atmosphere to the surface, where they add to Pluto's red coloring.

In a second significant finding, New Horizons has detected numerous small, exposed regions of water ice on Pluto. The discovery was made from data collected by the Ralph spectral composition mapper on New Horizons.

Above: Regions with exposed water ice are highlighted in blue in this composite image from New Horizons' Ralph instrument, combining visible imagery from the Multispectral Visible Imaging Camera (MVIC) with infrared spectroscopy from the Linear Etalon Imaging Spectral Array (LEISA).

The strongest signatures of water ice occur along Virgil Fossa, just west of Elliot crater on the left side of the inset image, and also in Viking Terra near the top of the frame. A major outcrop also occurs in Baré Montes towards the right of the image, along with numerous much smaller outcrops, mostly associated with impact craters and valleys between mountains. The scene is approximately 280 miles (450 kilometers) across. Note that all surface feature names are informal. (NASA/JHUAPL/SwRI)

"Large expanses of Pluto don't show exposed water ice," said science team member Jason Cook, of SwRI, "because it's apparently masked by other, more volatile ices across most of the planet. Understanding why water appears exactly where it does, and not in other places, is a challenge that we are digging into."

A curious aspect of the detection is that the areas showing the most obvious water ice spectral signatures correspond to areas that are bright red in recently released color images. "I'm surprised that this water ice is so red," says Silvia Protopapa, a science team member from the University of Maryland, College Park. "We don't yet understand the relationship between water ice and the reddish tholin colorants on Pluto's surface."

The New Horizons spacecraft is currently 3.1 billion miles (5 billion kilometers) from Earth, with all systems healthy and operating normally.

posted 10-16-2015 01:15 AM               

New Horizons Team Publishes First Research Paper on Pluto System Findings

Diversity of Pluto's landforms, atmosphere, and moons highlight the first three months of New Horizons data returns

The New Horizons team described a wide range of findings about the Pluto system in its first research paper, published today (Oct. 15). "The Pluto System: Initial Results from its Exploration by New Horizons" appears in and on the cover of the Oct. 16 issue of the journal Science; the publication comes just three months after NASA's historic first exploration of the Pluto system in mid-July. The authors include more than 150 New Horizons project and NASA personnel; Principal Investigator Alan Stern of Southwest Research Institute (SwRI) is first author.

From the variety in Pluto's geological landforms, to Pluto's atmosphere, to its intriguing moons, New Horizons has revealed a degree of diversity and complexity on Pluto and its moons that few expected in the frigid outer reaches of the solar system.

"The New Horizons mission completes our initial reconnaissance of the solar system, giving humanity our first look at this fascinating world and its system of moons," said Jim Green, director of planetary science at NASA Headquarters in Washington. "New Horizons is not only writing the textbook on the Pluto system, it's serving to inspire current and future generations to keep exploring — to keep searching for what's beyond the next hill."

NASA's New Horizons spacecraft reached a distance of 8,507 miles (13,691 kilometers) from Pluto's surface during its July 14 closest approach, gathering a treasure trove of data that will take almost another year to return to Earth. The data returned so far show a surprisingly wide variety of landforms and terrain ages on Pluto, as well as variations in color, composition, and albedo (surface reflectivity). Team members also discovered evidence for a water-ice rich crust and multiple haze layers in Pluto's atmosphere, and found that Pluto is both larger and more ice rich than expected prior to the flyby.

"The Pluto system surprised us in many ways, most notably teaching us that small planets can remain active billions of years after their formation," said Stern. "We were also taught important lessons by the unexpected degree of geological complexity that both Pluto and its large moon Charon display."

Observations of Pluto's moons show Charon has extensive resurfacing, extensional tectonics, and a puzzling dark terrain at its North Pole. Evidence also points to variations in the composition of its crust. Although no new satellites were detected, New Horizons provided the first resolved images of Pluto's smaller moons Nix and Hydra, finding Nix is approximately 34 miles (54 kilometers) long and Hydra is 27 miles (43 kilometers) long. Puzzlingly, their surface reflectivities are significantly higher than Charon's.

The spacecraft's science payload collected more than 50 gigabits of data from the Pluto system leading up to and at closest approach. Data were gathered by the suite of science instruments aboard New Horizons, including the Ralph infrared spectrometer/imager, the Long-Range Reconnaissance Imager (LORRI), the Alice ultraviolet spectrograph, twin REX radio science experiments, the Solar Wind Around Pluto (SWAP) detector, the PEPSSI charged-particle spectrometer, and a student-built and operated dust detector.

New Horizons is the first mission in NASA's New Frontiers program, managed by the agency's Marshall Space Flight Center in Huntsville, Ala. The Johns Hopkins University Applied Physics Laboratory designed, built, and operates the New Horizons spacecraft and manages the mission under Stern's direction for NASA's Science Mission Directorate. SwRI leads the science mission, payload operations, and encounter science planning.

posted 10-29-2015 02:41 PM               

Charon and the Small Moons of Pluto

Family Portrait of Pluto's Moons: This composite image shows a sliver of Pluto's large moon, Charon, and all four of Pluto's small moons, as resolved by the Long Range Reconnaissance Imager (LORRI) on the New Horizons spacecraft. All the moons are displayed with a common intensity stretch and spatial scale (see scale bar).

Charon is by far the largest of Pluto's moons, with a diameter of 751 miles (1,212 kilometers). Nix and Hydra have comparable sizes, approximately 25 miles (40 kilometers) across in their longest dimension above. Kerberos and Styx are much smaller and have comparable sizes, roughly 6-7 miles (10-12 kilometers) across in their longest dimension. All four small moons have highly elongated shapes, a characteristic thought to be typical of small bodies in the Kuiper Belt.

posted 10-29-2015 02:41 PM               

Pluto's Tiny Moon Kerberos

Kerberos appears to be smaller than scientists expected and has a highly-reflective surface, counter to predictions prior to the Pluto flyby in July. "Once again, the Pluto system has surprised us," said New Horizons Project Scientist Hal Weaver, of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.

The new data, downlinked from the New Horizons spacecraft on Oct. 20, show that Kerberos appears to have a double-lobed shape, with the larger lobe approximately 5 miles (8 kilometers) across and the smaller lobe approximately 3 miles (5 kilometers) across. Science team members speculate from its unusual shape that Kerberos could have been formed by the merger of two smaller objects. The reflectivity of Kerberos' surface is similar to that of Pluto's other small moons (approximately 50 percent) and strongly suggests Kerberos, like the others, is coated with relatively clean water ice.

Before the New Horizons encounter with Pluto, researchers had used Hubble Space Telescope images to "weigh" Kerberos by measuring its gravitational influence on its neighboring moons. That influence was surprisingly strong, considering how faint Kerberos was. They theorized that Kerberos was relatively large and massive, appearing faint only because its surface was covered in dark material. But the small, bright-surfaced Kerberos--now revealed in these new images--shows that the idea was incorrect, for reasons that are not yet understood.

"Our predictions were nearly spot-on for the other small moons, but not for Kerberos," said New Horizons co-investigator Mark Showalter, of the SETI Institute in Mountain View, California. The new results are expected to lead to a better understanding of Pluto's fascinating satellite system.

posted 10-29-2015 02:42 PM               

The Youngest Crater on Charon?

New Horizons scientists have discovered a striking contrast between one of the fresh craters on Pluto's largest moon Charon and a neighboring crater dotting the moon's Pluto-facing hemisphere.

Above: Charon's Young Ammonia Crater. The informally named Organa crater (shown in green) is rich in frozen ammonia and – so far – appears to be unique on Pluto's largest moon.

The crater, informally named Organa, caught scientists' attention as they were studying the highest-resolution infrared compositional scan of Charon. Organa and portions of the surrounding material ejected from it show infrared absorption at wavelengths of about 2.2 microns, indicating that the crater is rich in frozen ammonia – and, from what scientists have seen so far, unique on Pluto's largest moon. The infrared spectrum of nearby Skywalker crater, for example, is similar to the rest of Charon's craters and surface, with features dominated by ordinary water ice.

Above: This composite image is based on observations from the New Horizons Ralph/LEISA instrument made at 10:25 UT (6:25 a.m. EDT) on July 14, 2015, when New Horizons was 50,000 miles (81,000 kilometers) from Charon. The spatial resolution is 3 miles (5 kilometers) per pixel. The LEISA data were downlinked Oct. 1-4, 2015, and processed into a map of Charon's 2.2 micron ammonia-ice absorption band.

Long Range Reconnaissance Imager (LORRI) panchromatic images used as the background in this composite were taken about 8:33 UT (4:33 a.m. EDT) July 14 at a resolution of 0.6 miles (0.9 kilometers) per pixel and downlinked Oct. 5-6. The ammonia absorption map from LEISA is shown in green on the LORRI image. The region covered by the yellow box is 174 miles across (280 kilometers).

Using telescopes, scientists first observed ammonia absorption on Charon in 2000, but the concentrations of ammonia around this crater are unprecedented.

"Why are these two similar-looking and similar-sized craters, so near to each other, so compositionally distinct?" asked Will Grundy, New Horizons Composition team lead from Lowell Observatory in Flagstaff, Arizona. "We have various ideas when it comes to the ammonia in Organa. The crater could be younger, or perhaps the impact that created it hit a pocket of ammonia-rich subsurface ice. Alternatively, maybe Organa's impactor delivered its own ammonia."

Both craters are about the same size – roughly 5 kilometers [3 miles] in diameter – with similar appearances, including bright wisps or rays of ejected material, or ejecta. One apparent difference is that Organa has a central region of darker ejecta, though from the map created with data from New Horizons' Ralph/LEISA instrument, it appears that the ammonia-rich material extends beyond this dark area.

"This is a fantastic discovery," said Bill McKinnon, deputy lead for the New Horizons Geology, Geophysics and Imaging team from Washington University in St. Louis. "Concentrated ammonia is a powerful antifreeze on icy worlds, and if the ammonia really is from Charon's interior, it could help explain the formation of Charon's surface by cryovolcanism, via the eruption of cold, ammonia-water magmas."

posted 10-29-2015 02:42 PM               

Mapping Pluto's 'Broken Heart'

In addition to transmitting new high-resolution images and other data on the familiar close-approach hemispheres of Pluto and Charon, NASA's New Horizons spacecraft is also returning images – such as this one – to improve maps of other regions.

This image was taken by the New Horizons Long Range Reconnaissance Imager (LORRI) on the morning of July 13, 2015, from a range of 1.03 million miles (1.7 million kilometers) and has a resolution of 5.1 miles (8.3 kilometers) per pixel. It provides fascinating new details to help the science team map the informally named Krun Macula (the prominent dark spot at the bottom of the image) and the complex terrain east and northeast of Pluto's "heart" (Tombaugh Regio). Pluto's north pole is on the planet's disk at the 12 o'clock position of this image.

posted 10-29-2015 02:42 PM               

A Full View of Pluto's Stunning Crescent

In September, the New Horizons team released a stunning but incomplete image of Pluto's crescent. Thanks to new processing work by the science team, New Horizons is releasing the entire, breathtaking image of Pluto.

This image was made just 15 minutes after New Horizons' closest approach to Pluto on July 14, 2015, as the spacecraft looked back at Pluto toward the sun. The wide-angle perspective of this view shows the deep haze layers of Pluto's atmosphere extending all the way around Pluto, revealing the silhouetted profiles of rugged plateaus on the night (left) side. The shadow of Pluto cast on its atmospheric hazes can also be seen at the uppermost part of the disk. On the sunlit side of Pluto (right), the smooth expanse of the informally named icy plain Sputnik Planum is flanked to the west (above, in this orientation) by rugged mountains up to 11,000 feet (3,500 meters) high, including the informally named Norgay Montes in the foreground and Hillary Montes on the skyline. Below (east) of Sputnik, rougher terrain is cut by apparent glaciers.

The backlighting highlights more than a dozen high-altitude layers of haze in Pluto's tenuous atmosphere. The horizontal streaks in the sky beyond Pluto are stars, smeared out by the motion of the camera as it tracked Pluto. The image was taken with New Horizons' Multi-spectral Visible Imaging Camera (MVIC) from a distance of 11,000 miles (18,000 kilometers) to Pluto. The resolution is 700 meters (0.4 miles).

posted 11-05-2015 10:58 AM               

NASA's New Horizons Completes Record-Setting Kuiper Belt Targeting Maneuvers

NASA's New Horizons spacecraft has successfully performed the last in a series of four targeting maneuvers that set it on course for a potential January 2019 encounter with 2014 MU69. This ancient body in the Kuiper Belt is more than a billion miles beyond Pluto; New Horizons will explore it if NASA approves an extended mission.

The four propulsive maneuvers were the most distant trajectory corrections ever performed by any spacecraft. The fourth maneuver, programmed into the spacecraft's computers and executed with New Horizons' hydrazine-fueled thrusters, started at approximately 1:15 p.m. EST on Wednesday, Nov. 4, and lasted just under 20 minutes. Spacecraft operators at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, began receiving data through NASA's Deep Space Network just before 7 p.m. EST on Wednesday indicating the final targeting maneuver went as planned.

The maneuvers didn't speed or slow the spacecraft as much as they "pushed" New Horizons sideways, giving it a 57 meter per second (128 mile per hour) nudge toward the Kuiper Belt object (KBO). That's enough to allow New Horizons to intercept MU69 in just over three years.

"This is another milestone in the life of an already successful mission that's returning exciting new data every day," said Curt Niebur, New Horizons program scientist at NASA Headquarters in Washington. "These course adjustments preserve the option of studying an even more distant object in the future, as New Horizons continues its remarkable journey."

The New Horizons team will submit a formal proposal to NASA for the extended mission to 2014 MU69 in early 2016. The science team hopes to explore even closer to MU69 than New Horizons came to Pluto on July 14, which was approximately 7,750 miles (12,500 kilometers).

"New Horizons is healthy and now on course to make the first exploration of a building block of small planets like Pluto, and we're excited to propose its exploration to NASA," said New Horizons Principal Investigator Alan Stern of the Southwest Research Institute (SwRI), Boulder, Colorado.

The KBO targeting maneuvers were the mission's largest and longest, and carried out in a succession faster than any sequence of previous New Horizons engine burns. They were also accurate, performing almost exactly as they were designed and setting New Horizons on the course mission designers predicted. "The performance of each maneuver was spot on," said APL's Gabe Rogers, New Horizons spacecraft systems engineer and guidance and control lead.

The first three maneuvers were carried out on Oct. 22, 25 and 28. At the time of the Nov. 4 maneuver, New Horizons, speeding toward deeper space at more than 32,000 miles per hour, was approximately 84 million miles (135 million kilometers) beyond Pluto and nearly 3.2 billion miles (about 5.1 billion kilometers) from Earth. The spacecraft is currently 895 million miles (1.44 billion kilometers) from MU69. All systems remain healthy and the spacecraft continues to transmit data stored on its digital recorders from its flight through the Pluto system in July.

posted 11-09-2015 12:12 PM               

Four Months after Pluto Flyby, NASA's New Horizons Yields Wealth of Discovery

From possible ice volcanoes to twirling moons, NASA's New Horizons science team is discussing more than 50 exciting discoveries about Pluto at this week's 47th Annual Meeting of the American Astronomical Society's Division for Planetary Sciences in National Harbor, Maryland.

"The New Horizons mission has taken what we thought we knew about Pluto and turned it upside down," said Jim Green, director of planetary science at NASA Headquarters in Washington. "It's why we explore — to satisfy our innate curiosity and answer deeper questions about how we got here and what lies beyond the next horizon."

Above: Using New Horizons images of Pluto's surface to make 3-D topographic maps, scientists discovered that two of Pluto's mountains, informally named Wright Mons and Piccard Mons, could be ice volcanoes. The color depicts changes in elevation, blue indicating lower terrain and brown showing higher elevation. Green terrains are at intermediate heights.

For one such discovery, New Horizons geologists combined images of Pluto's surface to make 3-D maps that indicate two of Pluto's most distinctive mountains could be cryovolcanoes — ice volcanoes that may have been active in the recent geological past.

"It's hard to imagine how rapidly our view of Pluto and its moons are evolving as new data stream in each week. As the discoveries pour in from those data, Pluto is becoming a star of the solar system," said mission Principal Investigator Alan Stern of the Southwest Research Institute in Boulder, Colorado. "Moreover, I'd wager that for most planetary scientists, any one or two of our latest major findings on one world would be considered astounding. To have them all is simply incredible."

The two cryovolcano candidates are large features measuring tens of miles or kilometers across and several miles or kilometers high.

"These are big mountains with a large hole in their summit, and on Earth that generally means one thing — a volcano," said Oliver White, New Horizons postdoctoral researcher at NASA's Ames Research Center in Moffett Field, California. "If they are volcanic, then the summit depression would likely have formed via collapse as material is erupted from underneath. The strange hummocky texture of the mountain flanks may represent volcanic flows of some sort that have traveled down from the summit region and onto the plains beyond, but why they are hummocky, and what they are made of, we don't yet know."

While their appearance is similar to volcanoes on Earth that spew molten rock, ice volcanoes on Pluto are expected to emit a somewhat melted slurry of substances such as water ice, nitrogen, ammonia, or methane. If Pluto proves to have volcanoes, it will provide an important new clue to its geologic and atmospheric evolution.

"After all, nothing like this has been seen in the deep outer solar system," said Jeffrey Moore, New Horizons Geology, Geophysics and Imaging team leader, at Ames.

Pluto's Long History of Geologic Activity

Pluto's surface varies in age — from ancient, to intermediate, to relatively young — according to another new finding from New Horizons.

To determine the age of a surface area of the planet, scientists count crater impacts. The more crater impacts, the older the region likely is. Crater counts of surface areas on Pluto indicate that it has surface regions dating to just after the formation of the planets of our solar system, about four billion years ago.

But there also is a vast area that was, in geological terms, born yesterday — meaning it may have formed within the past 10 million years. This area, informally named Sputnik Planum, appears on the left side of Pluto's "heart" and is completely crater-free in all images received, so far.

New data from crater counts reveal the presence of intermediate, or "middle-aged," terrains on Pluto, as well. This suggests Sputnik Planum is not an anomaly — that Pluto has been geologically active throughout much of its more than 4-billion-year history.

"We've mapped more than a thousand craters on Pluto, which vary greatly in size and appearance," said postdoctoral researcher Kelsi Singer, of the Southwest Research Institute (SwRI) in Boulder, Colorado. "Among other things, I expect cratering studies like these to give us important new insights into how this part of the solar system formed."

Above: Locations of more than 1,000 craters mapped on Pluto by NASA's New Horizons mission indicate a wide range of surface ages, which likely means Pluto has been geologically active throughout its history.

Building Blocks of the Solar System

Crater counts are giving the New Horizons team insight into the structure of the Kuiper Belt itself. The dearth of smaller craters across Pluto and its large moon Charon indicate the Kuiper Belt, which is an unexplored outer region of our solar system, likely had fewer smaller objects than some models had predicted.

This leads New Horizons scientists to doubt a longstanding model that all Kuiper Belt objects formed by accumulating much smaller objects — less than a mile wide. The absence of small craters on Pluto and Charon support other models theorizing that Kuiper Belt objects tens of miles across may have formed directly, at their current — or close to current — size.

In fact, the evidence that many Kuiper Belt objects could have been "born large" has scientists excited that New Horizons' next potential target — the 30-mile-wide (40-50 kilometer wide) KBO named 2014 MU69 — which may offer the first detailed look at just such a pristine, ancient building block of the solar system.

Pluto's Spinning, Merged Moons

The New Horizons mission also is shedding new light on Pluto's fascinating system of moons, and their unusual properties. For example, nearly every other moon in the solar system — including Earth's moon — is in synchronous rotation, keeping one face toward the planet. This is not the case for Pluto's small moons.

Pluto's small lunar satellites are spinning much faster, with Hydra — its most distant moon — rotating an unprecedented 89 times during a single lap around the planet. Scientists believe these spin rates may be variable because Charon exerts a strong torque that prevents each small moon from settling down into synchronous rotation.

Another oddity of Pluto's moons: scientists expected the satellites would wobble, but not to such a degree.

"Pluto's moons behave like spinning tops," said co-investigator Mark Showalter of the SETI Institute in Mountain View, California.

Images of Pluto's four smallest satellites also indicate several of them could be the results of mergers of two or more moons.

Above: Data from NASA's New Horizons mission indicates that at least two — and possibly all four — of Pluto's small moons may be the result of mergers between still smaller moons. If this discovery is borne out with further analysis, it could provide important new clues to the formation of the Pluto system.

"We suspect from this that Pluto had more moons in the past, in the aftermath of the big impact that also created Charon," said Showalter.

To view more images and graphics being presented by New Horizons scientists at the 47th Annual Meeting of the American Astronomical Society's Division for Planetary Sciences, see here.

posted 12-04-2015 09:24 AM               

A Distant Close-up: New Horizons' Camera Captures a Wandering Kuiper Belt Object

NASA's New Horizons spacecraft recently took the closest images ever of a distant Kuiper Belt object – demonstrating its ability to observe numerous such bodies over the next several years if NASA approves an extended mission into the Kuiper Belt.

In this short animation, consisting of four frames taken by the spacecraft's Long Range Reconnaissance Imager (LORRI) on Nov. 2, and spaced an hour apart, one can see this 90-mile (150-kilometer)-wide ancient body, officially called 1994 JR1, moving against a background of stars. When these images were made, 1994 JR1 was 3.3 billion miles (5.3 billion miles) from the sun, but only 170 million miles (280 million kilometers) away from New Horizons. This sets a record, by a factor of at least 15, for the closest-ever picture of a small body in the Kuiper Belt, the solar system's "third zone" beyond the inner, rocky planets and outer, icy gas giants.

Mission scientists plan to use images like these to study many more ancient Kuiper Belt objects from New Horizons if an extended mission is approved. New Horizons flew through the Pluto system on July 14, making the first close-up observations of Pluto and its family of five moons. The spacecraft is on course for a close flyby of another Kuiper Belt object, 2014 MU69, on Jan. 1, 2019.

posted 03-17-2016 04:29 PM               

Science Papers Reveal New Aspects of Pluto and its Moons

A year ago, Pluto was just a bright speck in the cameras of NASA's approaching New Horizons spacecraft, not much different than its appearances in telescopes since Clyde Tombaugh discovered the then-ninth planet in 1930.

Above: This image of haze layers above Pluto's limb was taken by the Ralph/Multispectral Visible Imaging Camera (MVIC) on NASA's New Horizons spacecraft.

About 20 haze layers are seen; the layers have been found to typically extend horizontally over hundreds of kilometers, but are not strictly parallel to the surface. For example, scientists note a haze layer about 3 miles (5 kilometers) above the surface (lower left area of the image), which descends to the surface at the right. Credits: NASA/JHUAPL/SwRI/Gladstone et al./Science (2016)

But this week, in the journal Science, New Horizons scientists have authored the first comprehensive set of papers describing results from last summer's Pluto system flyby. "These five detailed papers completely transform our view of Pluto – revealing the former 'astronomer's planet' to be a real world with diverse and active geology, exotic surface chemistry, a complex atmosphere, puzzling interaction with the sun and an intriguing system of small moons," said Alan Stern, New Horizons principal investigator from the Southwest Research Institute (SwRI), Boulder, Colorado.

After a 9.5-year, 3-billion-mile journey – launching faster and traveling farther than any spacecraft to reach its primary target – New Horizons zipped by Pluto on July 14, 2015. New Horizons' seven science instruments collected about 50 gigabits of data on the spacecraft's digital recorders, most of it coming over nine busy days surrounding the encounter.

Above: Above are New Horizons' views of the informally named Sputnik Planum on Pluto (top) and the informally named Vulcan Planum on Charon (bottom). Both scale bars measure 20 miles (32 kilometers) long; illumination is from the left.

The bright, nitrogen-ice plains are defined by a network of crisscrossing troughs. This observation was obtained by the Ralph/Multispectral Visible Imaging Camera (MVIC) at a resolution of 1,050 feet (320 meters) per pixel.

The Vulcan Planum view in the bottom panel includes the "moated mountain" Clarke Mons just above the center of the image. The water ice-rich plains display a range of surface textures, from smooth and grooved at left, to pitted and hummocky at right. This observation was obtained by the Long Range Reconnaissance Imager (LORRI) at a resolution of 525 feet (160 meters) per pixel. Credits: NASA/JHUAPL/SwRI

The first close-up pictures revealed a large heart-shaped feature carved into Pluto's surface, telling scientists that this "new" type of planetary world – the largest, brightest and first-explored in the mysterious, distant "third zone" of our solar system known as the Kuiper Belt – would be even more interesting and puzzling than models predicted.

The newly published Science papers bear that out; click here for a list of top results.

"Observing Pluto and Charon up close has caused us to completely reassess thinking on what sort of geological activity can be sustained on isolated planetary bodies in this distant region of the solar system, worlds that formerly had been thought to be relics little changed since the Kuiper Belt's formation," said Jeff Moore, lead author of the geology paper from NASA's Ames Research Center, Moffett Field, California.

Scientists studying Pluto's composition say the diversity of its landscape stems from eons of interaction between highly volatile and mobile methane, nitrogen and carbon monoxide ices with inert and sturdy water ice. "We see variations in the distribution of Pluto's volatile ices that point to fascinating cycles of evaporation and condensation," said Will Grundy of the Lowell Observatory, Flagstaff, Arizona, lead author of the composition paper. "These cycles are a lot richer than those on Earth, where there's really only one material that condenses and evaporates – water. On Pluto, there are at least three materials, and while they interact in ways we don't yet fully understand, we definitely see their effects all across Pluto's surface."

Above the surface, scientists discovered Pluto's atmosphere contains layered hazes, and is both cooler and more compact than expected. This affects how Pluto's upper atmosphere is lost to space, and how it interacts with the stream of charged particles from the sun known as the solar wind. "We've discovered that pre-New Horizons estimates wildly overestimated the loss of material from Pluto's atmosphere," said Fran Bagenal, from the University of Colorado, Boulder, and lead author of the particles and plasma paper. "The thought was that Pluto's atmosphere was escaping like a comet, but it is actually escaping at a rate much more like Earth's atmosphere."

Above: This enhanced color view of Pluto's surface diversity was created by merging Ralph/Multispectral Visible Imaging Camera (MVIC) color imagery (650 meters or 2,132 feet per pixel) with Long Range Reconnaissance Imager panchromatic imagery (230 meters or 755 feet per pixel).

At lower right, ancient, heavily cratered terrain is coated with dark, reddish tholins. At upper right, volatile ices filling the informally named Sputnik Planum have modified the surface, creating a chaos-like array of blocky mountains. Volatile ice also occupies a few nearby deep craters, and in some areas the volatile ice is pocked with arrays of small sublimation pits.

At left, and across the bottom of the scene, gray-white methane ice deposits modify tectonic ridges, the rims of craters, and north-facing slopes. The scene in this image is 260 miles (420 kilometers) wide and 140 miles (225 kilometers) from top to bottom; north is to the upper left. Credits: NASA/JHUAPL/SwRI

SwRI's Randy Gladstone of San Antonio is the lead author of the Science paper on atmospheric findings. He added, "We've also discovered that methane, rather than nitrogen, is Pluto's primary escaping gas. This is pretty surprising, since near Pluto's surface the atmosphere is more than 99 percent nitrogen."

Scientists also are analyzing the first close-up images of Pluto's small moons—Styx, Nix, Kerberos and Hydra. Discovered between 2005 and 2012, the four moons range in diameter from about 25 miles (40 kilometers) for Nix and Hydra to about six miles (10 kilometers) for Styx and Kerberos. Mission scientists further observed that the small satellites have highly anomalous rotation rates and uniformly unusual pole orientations, as well as icy surfaces with brightness and colors distinctly different from those of Pluto and Charon.

They've found evidence that some of the moons resulted from mergers of even smaller bodies, and that their surface ages date back at least 4 billion years. "These latter two results reinforce the hypothesis that the small moons formed in the aftermath of a collision that produced the Pluto-Charon binary system," said Hal Weaver, New Horizons project scientist from the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, and lead author of the Science paper on Pluto's small moons.

About half of New Horizons' flyby data has now been transmitted home – from distances where radio signals at light speed need nearly five hours to reach Earth – with all of it expected back by the end of 2016.

"This is why we explore," said Curt Niebur, New Horizons program scientist at NASA Headquarters in Washington. "The many discoveries from New Horizons represent the best of humankind and inspire us to continue the journey of exploration to the solar system and beyond."

posted 05-19-2016 05:18 PM               

New Horizons' First Science on a Post-Pluto Object

Warming up for a possible extended mission as it speeds through deep space, NASA's New Horizons spacecraft has now twice observed 1994 JR1, a 90-mile (145-kilometer) wide Kuiper Belt object (KBO) orbiting more than 3 billion miles (5 billion kilometers) from the Sun. Science team members have used these observations to reveal new facts about this distant remnant of the early solar system.

Taken with the spacecraft's Long Range Reconnaissance Imager (LORRI) on April 7-8 from a distance of about 69 million miles (111 million kilometers), the images shatter New Horizons' own record for the closest-ever views of this KBO in November 2015, when New Horizons detected JR1 from 170 million miles (280 million kilometers) away.

Above: The first two of the 20 observations that New Horizons made of 1994 JR1 in April 2016. The Kuiper Belt object is the bright moving dot indicated by the arrow. The dots that do not move are background stars. The moving features in the top left and far right are internal camera reflections (a kind of selfie) caused by illumination by a very bright star just outside of LORRI's field of view; the one on the left shows the three arms that hold up LORRI's secondary mirror. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Simon Porter, a New Horizons science team member from Southwest Research Institute (SwRI) in Boulder, Colorado, said the observations contain several valuable findings. "Combining the November 2015 and April 2016 observations allows us to pinpoint the location of JR1 to within 1,000 kilometers (about 600 miles), far better than any small KBO," he said, adding that the more accurate orbit also allows the science team to dispel a theory, suggested several years ago, that JR1 is a quasi-satellite of Pluto.

From the closer vantage point of the April 2016 observations, the team also determined the object's rotation period, observing the changes in light reflected from its surface to determine that a JR1 "day" is 5.4 hours. "That's relatively fast for a KBO," said science team member John Spencer, also from SwRI. "This is all part of the excitement of exploring new places and seeing things never seen before."

Spencer added that these observations are great practice for possible close-up looks at about 20 more ancient Kuiper Belt objects that may come in the next few years, should NASA approve an extended mission. New Horizons flew through the Pluto system on July 14, 2015, making the first close-up observations of Pluto and its family of five moons. The spacecraft is on course for an ultra-close flyby of another Kuiper Belt object, 2014 MU69, on Jan. 1, 2019.

posted 07-01-2016 03:36 PM               

New Horizons Receives Mission Extension to Kuiper Belt

Following its historic first-ever flyby of Pluto, NASA's New Horizons mission has received the green light to fly onward to an object deeper in the Kuiper Belt, known as 2014 MU69. The spacecraft's planned rendezvous with the ancient object – considered one of the early building blocks of the solar system -- is Jan. 1, 2019.

"The New Horizons mission to Pluto exceeded our expectations and even today the data from the spacecraft continue to surprise," said NASA's Director of Planetary Science Jim Green. "We're excited to continue onward into the dark depths of the outer solar system to a science target that wasn't even discovered when the spacecraft launched."

posted 09-14-2016 01:03 PM               

Pluto 'Paints' its Largest Moon Red

In June 2015, when the cameras on NASA's approaching New Horizons spacecraft first spotted the large reddish polar region on Pluto's largest moon, Charon, mission scientists knew two things: they'd never seen anything like it elsewhere in our solar system, and they couldn't wait to get the story behind it.

Above: NASA's New Horizons spacecraft captured this high-resolution, enhanced color view of Pluto’s largest moon, Charon, just before closest approach on July 14, 2015. The image combines blue, red and infrared images taken by the spacecraft's Ralph/Multispectral Visual Imaging Camera (MVIC); the colors are processed to best highlight the variation of surface properties across Charon. CREDIT: NASA/JHUAPL/SwRI

Over the past year, after analyzing the images and other data that New Horizons has sent back from its historic July 2015 flight through the Pluto system, the scientists think they've solved the mystery. As they detail this week in the international scientific journal Nature, Charon's polar coloring comes from Pluto itself – as methane gas that escapes from Pluto's atmosphere and becomes "trapped" by the moon's gravity and freezes to the cold, icy surface at Charon's pole. This is followed by chemical processing by ultraviolet light from the sun that transforms the methane into heavier hydrocarbons and eventually into reddish organic materials called tholins.

"Who would have thought that Pluto is a graffiti artist, spray-painting its companion with a reddish stain that covers an area the size of New Mexico?" asked Will Grundy, a New Horizons co-investigator from Lowell Observatory in Flagstaff, Arizona, and lead author of the paper. "Every time we explore, we find surprises. Nature is amazingly inventive in using the basic laws of physics and chemistry to create spectacular landscapes."

The team combined analyses from detailed Charon images obtained by New Horizons with computer models of how ice evolves on Charon's poles. Mission scientists had previously speculated that methane from Pluto's atmosphere was trapped in Charon's north pole and slowly converted into the reddish material, but had no models to support that theory.

The New Horizons team dug into the data to determine whether conditions on the Texas-sized moon (with a diameter of 753 miles or 1,212 kilometers) could allow the capture and processing of methane gas. The models using Pluto and Charon's 248-year orbit around the sun show some extreme weather at Charon's poles, where 100 years of continuous sunlight alternate with another century of continuous darkness. Surface temperatures during these long winters dip to -430 Fahrenheit (-257 Celsius), cold enough to freeze methane gas into a solid.

"The methane molecules bounce around on Charon's surface until they either escape back into space or land on the cold pole, where they freeze solid, forming a thin coating of methane ice that lasts until sunlight comes back in the spring," Grundy said. But while the methane ice quickly sublimates away, the heavier hydrocarbons created from it remain on the surface.

The models also suggested that in Charon's springtime the returning sunlight triggers conversion of the frozen methane back into gas. But while the methane ice quickly sublimates away, the heavier hydrocarbons created from this evaporative process remain on the surface.

Sunlight further irradiates those leftovers into reddish material – called tholins – that has slowly accumulated on Charon's poles over millions of years. New Horizons' observations of Charon's other pole, currently in winter darkness – and seen by New Horizons only by light reflecting from Pluto, or "Pluto-shine" – confirmed that the same activity was occurring at both poles.

"This study solves one of the greatest mysteries we found on Charon, Pluto's giant moon," said Alan Stern, New Horizons principal investigator from the Southwest Research Institute, and a study co-author. "And it opens up the possibility that other small planets in the Kuiper Belt with moons may create similar, or even more extensive 'atmospheric transfer' features on their moons."

posted 10-27-2016 10:32 AM               

New Horizons Returns Last Bits of 2015 Flyby Data to Earth

NASA's New Horizons mission reached a major milestone this week when the last bits of science data from the Pluto flyby – stored on the spacecraft's digital recorders since July 2015 – arrived safely on Earth.

Having traveled from the New Horizons spacecraft over 3.4 billion miles, or 5.5 billion kilometers (five hours, eight minutes at light speed), the final item – a segment of a Pluto-Charon observation sequence taken by the Ralph/LEISA imager – arrived at mission operations at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, at 5:48 a.m. EDT on Oct. 25. The downlink came via NASA's Deep Space Network station in Canberra, Australia. It was the last of the 50-plus total gigabits of Pluto system data transmitted to Earth by New Horizons over the past 15 months.

"The Pluto system data that New Horizons collected has amazed us over and over again with the beauty and complexity of Pluto and its system of moons," said Alan Stern, New Horizons principal investigator from Southwest Research Institute in Boulder, Colorado. "There's a great deal of work ahead for us to understand the 400-plus scientific observations that have all been sent to Earth. And that's exactly what we're going to do—after all, who knows when the next data from a spacecraft visiting Pluto will be sent?"

Because it had only one shot at its target, New Horizons was designed to gather as much data as it could, as quickly as it could – taking about 100 times more data on close approach to Pluto and its moons than it could have sent home before flying onward. The spacecraft was programmed to send select, high-priority datasets home in the days just before and after close approach, and began returning the vast amount of remaining stored data in September 2015.

"We have our pot of gold," said Mission Operations Manager Alice Bowman, of APL.

Bowman said the team will conduct a final data-verification review before erasing the two onboard recorders, and clearing space for new data to be taken during the New Horizons Kuiper Belt Extended Mission (KEM) that will include a series of distant Kuiper Belt object observations and a close encounter with a small Kuiper Belt object, 2014 MU69, on Jan. 1, 2019.

posted 02-10-2017 11:48 AM               

New Horizons Exits Brief Safe Mode, Recovery Operations Continue

NASA's New Horizons spacecraft is operating normally after just over 24 hours in a protective "safe mode," the result of a command-loading error that occurred early Thursday (Feb. 9).

The spacecraft is designed to automatically transition to safe mode under certain anomalous conditions to protect itself from harm. In safe mode, the spacecraft suspends its timeline of activities and keeps its antenna pointed toward Earth to listen for instructions from the Mission Operations Center at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland.

"Our rapid recovery was supported by other NASA missions that provided New Horizons with some of their valuable Deep Space Network [DSN] antenna time," said Alice Bowman, New Horizons mission operations manager at APL. "This is the norm for missions using the DSN – we support one another when challenges arise."

New Horizons is healthy and continues to speed along toward its next target – the Kuiper Belt object 2014 MU69 – while its operations team works to restore it to full operations and resume scientific data collection. Due to the 10.5-hour round trip communications delay that results from operating a spacecraft more than 3.5 billion miles (5.7 billion kilometers) from Earth, the team expects New Horizons to be back on its activities timeline early Sunday, Feb. 12.

posted 02-23-2017 08:20 AM               

NASA's New Horizons, IAU Set Pluto Naming Themes

The International Astronomical Union (IAU) – the internationally recognized authority for naming celestial bodies and their surface features – has approved themes submitted by NASA's New Horizons team for naming surface features on Pluto and its moons.

In 2015, NASA's New Horizons spacecraft delivered the first close-up views of Pluto and its five moons – amazing images of distant and surprisingly complex worlds, showing a vast nitrogen glacier as well as ice mountains, canyons, cliffs, craters and more. The IAU's action clears the way for the mission team to propose formal names for dozens of individual surface features.

"Imagine the thrill of seeing your name suggestion on a future map of Pluto and its moons," said Jim Green, director of NASA's Planetary Science Division in Washington. "Months after the Pluto flyby, the New Horizons mission continues to engage and inspire."

Working with the New Horizons team, the IAU has agreed to naming themes (listed below) for Pluto, its largest moon, Charon, and its four smaller moons—Styx, Nix, Kerberos, and Hydra. Some of these themes build on the connection between the Roman god Pluto and the mythology of the underworld. Other themes celebrate the human spirit of exploration.

Pluto

• Gods, goddesses and other beings associated with the underworld from mythology, folklore and literature
  
• Names for the underworld and for underworld locales from mythology, folklore and literature
  
• Heroes and other explorers of the underworld
  
• Scientists and engineers associated with Pluto and the Kuiper Belt
  
• Pioneering space missions and spacecraft
  
• Historic pioneers who crossed new horizons in the exploration of the Earth, sea and sky

Charon

• Destinations and milestones of fictional space and other exploration
  
• Fictional and mythological vessels of space and other exploration
  
• Fictional and mythological voyagers, travelers and explorers
  
• Authors and artists associated with space exploration, especially Pluto and the Kuiper Belt

Themes for Pluto's smaller moons are:

• Styx: River gods
  
• Nix: Deities of the night
  
• Kerberos: Dogs from literature, mythology and history
  
• Hydra: Legendary serpents and dragons

As a precursor to the naming process now underway between the IAU and New Horizons, in early 2015 the IAU endorsed the NASA-New Horizons led "Our Pluto" naming campaign, which allowed the public to participate in the exploration of Pluto by proposing names for surface features that were still awaiting discovery. That campaign was a partnership between the mission, NASA and the SETI Institute, of Mountain View, California.

"I'm very happy with both the process and partnership that New Horizons and the IAU undertook that led to wonderful, inspiring, and engaging naming themes for surface features on Pluto and its moons," said Alan Stern, New Horizons principal investigator from Southwest Research Institute, Boulder, Colorado. "We look forward to the next step—submitting actual feature names for approval."

posted 04-05-2017 10:50 AM               

New Horizons Halfway from Pluto to Next Flyby Target

How time and our spacecraft fly – especially when you're making history at 32,000 miles (51,500 kilometers) per hour.

Continuing on its path through the outer regions of the solar system, NASA's New Horizons spacecraft has now traveled half the distance from Pluto – its storied first target – to 2014 MU69, the Kuiper Belt object (KBO) it will fly past on Jan. 1, 2019. The spacecraft reached that milestone at midnight (UTC) on April 3 – or 8 p.m. ET on April 2 – when it was 486.19 million miles (782.45 million kilometers) beyond Pluto and the same distance from MU69.

"It's fantastic to have completed half the journey to our next flyby; that flyby will set the record for the most distant world ever explored in the history of civilization," said Alan Stern, New Horizons principal investigator from the Southwest Research Institute in Boulder, Colorado.

Later this week – at 21:24 UTC (or 5:24 p.m. ET) on April 7 – New Horizons will also reach the halfway point in time between closest approaches to Pluto, which occurred at 7:48 a.m. ET on July 14, 2015, and MU69, predicted for 2 a.m. ET on New Year's Day 2019. The nearly five-day difference between the halfway markers of distance and time is due to the gravitational tug of the sun. The spacecraft is actually getting slightly slower as it pulls away from the sun's gravity, so the spacecraft crosses the midpoint in distance a bit before it passes the midpoint in time.

Ready for a Rest

New Horizons will begin a new period of hibernation later this week. In fact, the spacecraft will be sleeping through the April 7 halfway timing marker to MU69, because mission operators at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, will have put the spacecraft into hibernation two hours beforehand.

The scheduled 157-day hibernation is well-deserved; New Horizons has been "awake" for almost two and a half years, since Dec. 6, 2014. Since then, in addition to its historic Pluto encounter and 16 subsequent months of relaying the data from that encounter back to Earth, New Horizons has made breakthrough, distant observations of a dozen Kuiper Belt objects (KBOs), collected unique data on the dust and charged-particle environment of the Kuiper Belt, and studied the hydrogen gas that permeates the vast space surrounding the sun, called the heliosphere.

"The January 2019 MU69 flyby is the next big event for us, but New Horizons is truly a mission to more broadly explore the Kuiper Belt," said Hal Weaver, New Horizons project scientist from APL, in Laurel, Maryland. "In addition to MU69, we plan to study more than two-dozen other KBOs in the distance and measure the charged particle and dust environment all the way across the Kuiper Belt."

New Horizons is currently 3.5 billion miles (5.7 billion kilometers) from Earth; at that distance, a radio signal sent from the operations team – and traveling at light speed – needs about five hours and 20 minutes to reach the spacecraft. All spacecraft systems are healthy and operating normally, and the spacecraft is on course for its MU69 flyby.

posted 04-11-2017 08:46 AM               

Nap Time for New Horizons: NASA Spacecraft Enters Hibernation

NASA's New Horizons spacecraft has eased into a long summer's nap, entering a hibernation phase on April 7 that will last until early September.

Mission controllers at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, verified that New Horizons – acting on commands uplinked to its main computer the week before – entered hibernation at 3:32 p.m. EDT. With the spacecraft now about 3.5 billion miles (5.7 billion kilometers) from Earth, the radio signals carrying that word from New Horizons needed just over five hours – traveling at the speed of light – to reach the APL mission operations center through NASA's Deep Space Network.

Before today, New Horizons had been "awake" for almost two and a half years, since Dec. 6, 2014, when the team began final preparations for Pluto approach and encounter operations. The 852 days since the end of its last hibernation period is the longest – by far – New Horizons has remained in active operations since it was launched in January 2006.

But that's because New Horizons was in the throes of its prime mission: conducting a six-month flyby of the Pluto system that culminated with close approach on July 14, 2015; that was followed by 16 months transmitting the data from that flight back to Earth. The spacecraft then began an extended mission in the Kuiper Belt, making distant observations of several Kuiper Belt objects – setting up for a close flyby on Jan. 1, 2019, of one particular object known as 2014 MU69 – and sampling the space environment in the outer reaches of the solar system.

"We're looking forward taking advantage of the reduced mission operations workload during this hibernation, as well as one early next year, to plan much of the MU69 flyby," said Alice Bowman, New Horizons mission operations manager, from APL.

This hibernation period will last 157 days – ending on Sept. 11 – but mission activity won't necessarily stop. The science and mission operations teams will be developing detailed command loads for the MU69 encounter, shaping the science observations for much of nine-day flyby. Their plans currently accommodate two potential flyby altitudes; the team will narrow its choice to the final altitude as it learns more about the properties and orbit of MU69, which was discovered less than three years ago.

A Hibernation Refresher

During hibernation mode, much of the New Horizons spacecraft is unpowered. The onboard flight computer monitors system health and broadcasts a weekly beacon-status tone back to Earth, and about once a month sends home data on spacecraft health and safety. Onboard sequences sent in advance by mission controllers will eventually wake New Horizons to check out critical systems, gather new Kuiper Belt science data, and perform course corrections (if necessary).

New Horizons pioneered routine cruise-flight hibernation for NASA. Not only has hibernation reduced wear and tear on the spacecraft's electronics, it also lowered operations costs and freed up NASA Deep Space Network tracking and communication resources for other missions.

posted 05-26-2017 08:23 PM               

New Horizons Deploys Global Team for Rare Look at Next Flyby Target

On New Year's Day 2019, more than 4 billion miles from home, NASA's New Horizons spacecraft will race past a small Kuiper Belt object known as 2014 MU69 – making this rocky remnant of planetary formation the farthest object ever encountered by any spacecraft.

But over the next six weeks, the New Horizons mission team gets an "MU69" preview of sorts – and a chance to gather some critical encounter-planning information – with a rare look at their target object from Earth.

On June 3, and then again on July 10 and July 17, MU69 will occult – or block the light from – three different stars, one on each date. To observe the June 3 "stellar occultation," more than 50 team members and collaborators are deploying along projected viewing paths in Argentina and South Africa. They'll fix camera-equipped portable telescopes on the occultation star and watch for changes in its light that can tell them much about MU69 itself.

"Our primary objective is to determine if there are hazards near MU69 – rings, dust or even satellites – that could affect our flight planning," said New Horizons Principal Investigator Alan Stern, of Southwest Research Institute (SwRI) in Boulder, Colorado. "But we also expect to learn more about its orbit and possibly determine its size and shape. All of that will help feed our flyby planning effort."

What Are They Looking At?

In simplest terms, an astronomical occultation is when something moves in front of, or occults, something else. "When the moon passes in front of the sun and we have a solar eclipse, that's one kind of occultation," said Joel Parker, a New Horizons co-investigator from SwRI. "If you're in the path of an eclipse, it means you're in the path of the shadow on Earth that's created by the moon passing between us and the sun. If you're standing in the right place at the right time, the solar eclipse can last up to a few minutes."

The team will have no such luxury with the MU69 occultations. Marc Buie, the New Horizons co-investigator from SwRI who is leading the occultation observations, said that because MU69 is so small – thought to be about 25 miles (40 kilometers) across – the occultations should only last about two seconds. But scientists can learn a lot from even that, and observations from several telescopes that see different parts of the shadow can reveal information about an object's shape as well as its brightness.

A Space Challenge

The mission team has 22 new, portable 16-inch (40-centimeter) telescopes at the ready, along with three others portables and over two-dozen fixed-base telescopes that will be located along the occultation path through Argentina and South Africa. But deciding exactly where to place them was a challenge. This particular Kuiper Belt object was discovered just three years ago, so its orbit is still largely unknown. Without a precise fix on the object's position – or on the exact path its narrow shadow might take across Earth – the team is spacing the telescope teams along "picket fence lines," one every 6 to 18 miles (10 or 25 kilometers), to increase the odds that at least one or more of the portable telescopes will catch the center of the event and help determine the size of MU69.

The other telescopes will provide multiple probes for debris that could be a danger to the fast-moving New Horizons spacecraft when it flies by MU69 at about 35,000 miles per hour (56,000 kilometers per hour), on Jan. 1, 2019.

"Deploying on two different continents also maximizes our chances of having good weather," said New Horizons Deputy Project Scientist Cathy Olkin, from SwRI. "The shadow is predicted to go across both locations and we want observers at both, because we wouldn't want a huge storm system to come through and cloud us out — the event is too important and too fleeting to miss."

The team gets help from above for the July 10 occultation, adding the powerful 100-inch (2.5-meter) telescope on NASA's airborne Stratospheric Observatory for Infrared Astronomy (SOFIA). Enlisting SOFIA, with its vantage point above the clouds, takes the bad weather factor out of the picture. The plane also should be able to improve its measurements by maneuvering into the very center of the occultation shadow.

Insight for Encounter Planning

Any information on MU69, gathered from the skies or on the ground, is welcome. Carly Howett, deputy principal investigator of New Horizons' Ralph instrument, of SwRI, said so little is known about MU69 that the team is planning observations of a target it doesn't fully understand – and time to learn more about the object is short. "We were only able to start planning the MU69 encounter after we flew by Pluto in 2015," she said. "That gives us two years, instead of almost seven years we had to plan the Pluto encounter. So it's a very different and, in many ways, more challenging flyby to plan."

If weather cooperates and predicted targeting proves on track, the upcoming occultation observations could provide the first precise size and reflectivity measurements of MU69. These figures will be key to planning the flyby itself – knowing the size of the object and the reflectivity of its surface, for example, helps the team set exposure times on the spacecraft's cameras and spectrometers.

"Spacecraft flybys are unforgiving," Stern said. "There are no second chances. The upcoming occultations are valuable opportunity to learn something about MU69 before our encounter, and help us plan for a very unique flyby of a scientifically important relic of the solar system's era of formation."

Follow the observations in Argentina, South Africa and on board SOFIA on Facebook and Twitter using #mu69occ.

posted 08-03-2017 01:47 PM               

New Horizons' Next Target Just Got a Lot More Interesting

Could the next flyby target for NASA's New Horizons spacecraft actually be two targets?

New Horizons scientists look to answer that question as they sort through new data gathered on the distant Kuiper Belt object (KBO) 2014 MU69, which the spacecraft will fly past on Jan. 1, 2019. That flyby will be the most distant in the history of space exploration, a billion miles beyond Pluto.

Above: One artist's concept of Kuiper Belt object 2014 MU69, the next flyby target for NASA's New Horizons mission. This binary concept is based on telescope observations made at Patagonia, Argentina on July 17, 2017 when MU69 passed in front of a star. New Horizons theorize that it could be a single body with a large chunk taken out of it, or two bodies that are close together or even touching. (NASA/JHUAPL/SwRI/Alex Parker)

The ancient KBO, which is more than four billion miles (6.5 billion kilometers) from Earth, passed in front of a star on July 17, 2017. A handful of telescopes deployed by the New Horizons team in a remote part of Patagonia, Argentina were in the right place at the right time to catch its fleeting shadow — an event known as an occultation – and were able to capture important data to help mission flyby planners better determine the spacecraft trajectory and understand the size, shape, orbit and environment around MU69.

Based on these new occultation observations, team members say MU69 may not be not a lone spherical object, but suspect it could be an "extreme prolate spheroid" – think of a skinny football – or even a binary pair. The odd shape has scientists thinking two bodies may be orbiting very close together or even touching – what's known as a close or contact binary – or perhaps they're observing a single body with a large chunk taken out of it. The size of MU69 or its components also can be determined from these data. It appears to be no more than 20 miles (30 kilometers) long, or, if a binary, each about 9-12 miles (15-20 kilometers) in diameter.

"This new finding is simply spectacular. The shape of MU69 is truly provocative, and could mean another first for New Horizons going to a binary object in the Kuiper Belt," said Alan Stern, mission principal investigator from the Southwest Research Institute (SwRI) in Boulder, Colorado. "I could not be happier with the occultation results, which promise a scientific bonanza for the flyby."

Above: Second artist's concept of Kuiper Belt object 2014 MU69, which is the next flyby target for NASA's New Horizons mission. Scientists speculate that the Kuiper Belt object could be a single body (above) with a large chunk taken out of it, or two bodies (main image) that are close together or even touching. (NASA/JHUAPL/SwRI/Alex Parker)

The July 17 stellar occultation event that gathered these data was the third of a historic set of three ambitious occultation observations for New Horizons. The team used data from the Hubble Space Telescope and European Space Agency's Gaia satellite to calculate and pinpoint where MU69 would cast a shadow on Earth's surface. "Both of these space satellites were crucial to the success of the entire occultation campaign," added Stern.

Said Marc Buie, the New Horizons co-investigator who led the observation campaign, "These exciting and puzzling results have already been key for our mission planning, but also add to the mysteries surrounding this target leading into the New Horizons encounter with MU69, now less than 17 months away."

posted 09-06-2017 02:31 PM               

New Horizons Files Flight Plan for 2019 Flyby

NASA's New Horizons mission has set the distance for its New Year's Day 2019 flyby of Kuiper Belt object 2014 MU69, aiming to come three times closer to MU69 than it famously flew past Pluto in 2015.

Above: Artist's concept of NASA's New Horizons spacecraft flying by a possible binary 2014 MU69 on Jan. 1, 2019. Early observations of MU69 hint at the Kuiper Belt object being either a binary orbiting pair or a contact (stuck together) pair of nearly like-sized bodies with diameters near 20 and 18 kilometers (12 and 11 miles). (Carlos Hernandez)

That milestone will mark the farthest planetary encounter in history – some one billion miles (1.5 billion kilometers) beyond Pluto and more than four billion miles (6.5 billion kilometers) from Earth. If all goes as planned, New Horizons will come to within just 2,175 miles (3,500 kilometers) of MU69 at closest approach, peering down on it from celestial north. The alternate plan, to be employed in certain contingency situations such as the discovery of debris near MU69, would take New Horizons within 6,000 miles (10,000 kilometers) — still closer than the 7,800-mile (12,500-kilometer) flyby distance to Pluto.

"I couldn't be more excited about this encore performance from New Horizons," said NASA Planetary Science Director Jim Green at Headquarters in Washington. "This mission keeps pushing the limits of what's possible, and I'm looking forward to the images and data of the most distant object any spacecraft has ever explored."

If the closer approach is executed, the highest-resolution camera on New Horizons, the telescopic Long Range Reconnaissance Imager (LORRI) should be able to spot details as small as 230 feet (70 meters) across, for example, compared to nearly 600 feet (183 meters) on Pluto.

"We're planning to fly closer to MU69 than Pluto to get even higher resolution imagery and other datasets," said New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute (SwRI), Boulder, Colorado. "The science should be spectacular."

The team weighed numerous factors in making its choice, said science team member and flyby planning lead John Spencer, also of SwRI. "The considerations included what is known about MU69's size, shape and the likelihood of hazards near it, the challenges of navigating close to MU69 while obtaining sharp and well-exposed images, and other spacecraft resources and capabilities," he said.

Using all seven onboard science instruments, New Horizons will obtain extensive geological, geophysical, compositional, and other data on MU69; it will also search for an atmosphere and moons.

"Reaching 2014 MU69, and seeing it as an actual new world, will be another historic exploration achievement," said Helene Winters, the New Horizons project manager from the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. "We are truly going where no one has gone before. Our whole team is excited about the challenges and opportunities of a voyage to this faraway frontier."