Approach Data| Approach Data Flyby Data Downloaded Data |
The New Horizons spacecraft had come out of hibernation on Dec. 6, 2014 and turned into active mode from the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. In the New Horizons Mission Operations Center at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, flight controllers performed a short course correction maneuver on June 29th, 2015, which refined New Horizons path toward Pluto flyby on next July 14, with the craft's velocity modified by just about one-half mile per hour (27 centimeters per second). The 23-second thruster burst was the third and final planned targeting maneuver of New Horizons’ approach phase to Pluto, after that of March 10 and June 15, 2015. Nine course corrections in total occurred since New Horizons launched in January 2006. New Horizons now is on course to a flyby close-approach target point approximately 7,750 miles (12,500 kilometers) above Pluto’s surface. Timing and accuracy are critical for all New Horizons flyby observations, since commands are now stored in the spacecraft’s computers and programmed to execute at exact times. The craft now is set to fly right down the middle of the optimal approach corridor. As the spacecraft will fly inside the orbits of all five of Pluto’s known moons, the New Horizons team has completed several hazard-search observations of the Pluto system, looking for a highly sensitive search for faint satellites, rings or dust-sheets in the system and the team has until July 4, 2015 to divert the spacecraft to one of three alternate routes if any dangers are found. During the approach phase, miscellaneous pictures were taken, showing that both Pluto and Charon feature varied terrain, as the infrared spectrometer also detected frozen methane on Pluto’s surface. The deed already had been observed from Earth-based observatories -of which a astronomer member of the New Horizons team- in 1976. On Pluto, methane may be primordial, inherited from the solar nebula from which the solar system formed 4.5 billion years ago
New Horizons flight controllers celebrated after they received confirmation from the spacecraft that it had successfully completed the flyby of Pluto, Tuesday, July 14, 2015 in the Mission Operations Center (MOC) of the Johns Hopkins University Applied Physics Laboratory (APL), Laurel, Maryland. The call was 'phoned' just before 9 p.m. EDT Tuesday, July 14th, 2015. It consisted into a 15-minute series of status messages beamed back through NASA’s Deep Space Network, ending a very suspenseful 21-hour waiting period. New Horizons had been instructed to spend the day gathering the maximum amount of data, and not communicating with Earth until it was beyond the Pluto system. Mission scientists have found Pluto to be 1,473 miles (2,370 kilometers; 18,5% that of Earth) in diameter, somewhat larger than many prior estimates, making Pluto larger than all other known solar system objects beyond the orbit of Neptune. The size of Pluto had been debated since its discovery in 1930 as complicating factors had been the planet's atmosphere, and the New Horizons missions thus finally laid the question to rest. Pluto’s newly estimated size means that its density is slightly lower than previously thought, and the fraction of ice in its interior is slightly higher. Also, the lowest layer of Pluto’s atmosphere, called the troposphere, is shallower than previously believed. New Horizons observations of Charon, on a other hand, confirm previous estimates of 751 miles (1,208 km; 35 percent of Moon's diameter) across
 | Pluto getting larger as seen by approaching New Horizons!. picture courtesy site 'Amateur Astronomy' |
 | Charon, main Pluto's satellite, getting larger as seen by approaching New Horizons!. picture courtesy site 'Amateur Astronomy' |
The New Horizons spacecraft experienced an anomaly the afternoon of July 4 that led to a loss of communication with Earth and a stop of science activity. The failure occurred after mission controllers at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, uploaded the final sequence of commands for the flyby the previous day. Coms were regained few after as the work had been hampered due to the 9-hour, round trip com delay between the craft and the Earth. For the same reasons, full recovery is expected to take from one to several days and craft returned to normal operations about July 7, 2015. The underlying cause of the incident was a hard-to-detect timing flaw in the spacecraft command sequence that occurred during an operation to prepare for the close flyby. NASA’s New Horizons spacecraft, on a other hand, got a final all clear on July 1st, 2015 as, after seven weeks of detailed searches for dust clouds, rings, and other potential hazards, and the New Horizons team decided the spacecraft will remain on its original path through the Pluto system instead of making a late course correction to detour around any hazards. New Horizons is traveling at 30,800 mph (49,600 kph). New Horizons hazard analysis team had been formed in 2011, after the discovery of Pluto’s fourth moon, Kerberos, raised concerns the cratering of these moons by small debris from the outer area of the solar system known as the Kuiper Belt, could spread additional hazardous debris into New Horizons’ path. Reddish brown color at Pluto is likely caused by hydrocarbon molecules that are formed when cosmic rays and solar ultraviolet light, called Lyman alpha, interact with methane in Pluto’s atmosphere and on its surface, powering chemical reactions that create complex compounds called tholins. The tholins drop to the ground to form a reddish coat. Pluto’s reddish color has been known for decades as the reddening process occurs even on the night side where there’s no sunlight, and in the depths of winter. Methane can also yield snow at Pluton like seen at some mountains' tops, from the planet's atmosphere. Charon’s dark, red polar cap is unprecedented in the solar system and may be the result of atmospheric gases that escaped Pluto and then accreted on Charon’s surface. It might be due to methane gas escaping from Pluto’s atmosphere and being trapped by the moon’s gravity and freezing to the cold, icy surface at Charon’s pole. Chemical processing by ultraviolet light from the Sun then transforms the methane into heavier hydrocarbons and eventually into reddish organic materials called tholins
 | That most accurate picture of Pluto taken one day before July 14th, 2015 flyby is showing more details about the planet's terrains. The light area on Pluto is estimated to be 1,000 miles (1,600 kilometers) across at its widest point, which rests just above the equator. In the north polar cap, methane ice is diluted in a thick, transparent slab of nitrogen ice as miscellanesous textures of methane are seen also. The most accurate picture of Charon taken in the same conditions, is showing a swath of cliffs and troughs stretches about 600 miles (1,000 kilometers), suggesting widespread fracturing of Charon’s crust. Mission scientists are surprised by the apparent lack of craters on Charon. Dark marking prominent in the northern region has a diffuse boundary, suggesting it is a thin deposit of dark material as a underlying sharply bounded, angular feature is seen under. Such views might suggest that Charon, or even Pluto suffered a impact which triggered a fracture. Unlike the icy moons of giant planets, no gravitational interactions in the Plutonian system are extant to provide for geological activity. That may cause us to rethink what powers geological activity on icy worlds. picture site 'Amateur Astronomy' based upon pictures NASA-JHUAPL-SwRI |
 | Pluto's moon Hydra has been first revealed during the flyby, with a irregularly shaped body characterized by significant brightness variations over the surface. Like that of Charon, Hydra's surface is probably covered with water ice. The view, right, has been added from data sent after the flyby. New compositional data worked out after the flyby, reveal that the surface of Pluto’s outermost moon, Hydra, is dominated by nearly crystalline pristine water ice explaining the moon's highly reflective surface. The Hydra spectrum is similar to that of Pluto’s largest moon, Charon. Spectrum data are suggesting that ice grains on Hydra’s surface are larger or reflect more light at certain angles than the grains on Charon. Hydra is thought to have formed in an icy debris disk produced when water-rich mantles were stripped from the two bodies that collided to form the Pluto-Charon binary some 4 billion years ago. Hydra's surface also implies relatively little contamination by darker material that has accumulated on Charon's surface over time, which might be due to micrometeorite impacts continually refreshing the surface of Hydra by blasting off contaminants. Such a process would have been ineffective on the much larger Charon, whose much stronger gravity retains any debris created by these impacts. picture site 'Amateur Astronomy' based upon pictures NASA-JHUAPL-SwRI |
 | A vast, craterless plain that appears to be no more than 100 million years old, and is possibly still being shaped by geologic processes, is lying in the center left of Pluto's vast light area. 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. picture site 'Amateur Astronomy' based upon a picture NASA-JHUAPL-SwRI |
 | Homing in on Pluto's small satellite Nix, New Horizons' Long Range Reconnaissance Imager captured this image, which shows features as small as 4 miles (6 kilometers across). Mission scientists believe we are looking at one end of an elongated body about 25 miles (40 kilometers) in diameter. The image was acquired on July 13 from a distance of about 360,000 miles (590,000 kilometers). picture site 'Amateur Astronomy' based upon a picture NASA-JHUAPL-SwRI |
 | Pluto’s predominantly nitrogen atmosphere lets some of its molecules escape into space, where they are ionized by solar ultraviolet radiation. As the solar wind encounters the obstacle formed by the ions, it is slowed and diverted (depicted in the red region), possibly forming a shock wave upstream of Pluto. The ions are 'picked up' by the solar wind and carried in its flow past the dwarf planet tens of thousands of miles beyond to form an ion or plasma tail (blue region). picture site 'Amateur Astronomy' based upon a picture NASA |
 | At the center of the 'heart of Pluto,' New Horizons’ 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. picture site 'Amateur Astronomy' based upon a picture NASA |
 | Diminutive Pluto's moons Nix (right, enhanced colors) and Hydra (left) are seen on that picture. A reddish region at Nix might be a crater as two large craters might be seen at Hydra. The rightmost view of Nix was issued after the July 14th flyby at a range of about 14,000 miles (23,000 kilometers) with the illuminated surface about 12 miles (19 kilometers) by 29 miles (47 kilometers). picture site 'Amateur Astronomy' based pictures NASA/JHUAPL/SWRI |
 | Nix surface is covered in water ice, similar to what exist to Hydra. Compared to Charon and Hydra, relative to pure water ice, Nix's surface displays the deepest water-ice spectral features, hinting to a water ice relatively coarse-grained and pure. Pluto’s small satellites --Nix, Hydra along with Styx and Kerberos-- probably all formed out of the cloud of debris created by the impact of a small planet onto a young Pluto. Science team is puzzling over why Nix and Hydra apparently have different ice textures on their surfaces despite their similar sizes as a other mystery is why Hydra’s surface reflectivity at visible wavelengths is higher than Nix’s even though Nix’s surface appears to be icier, implying higher reflectivity at visible wavelengths. picture NASA/JHUAPL/SwRI |
 | A newly discovered mountain range lies between bright, icy plains and dark, heavily-cratered terrain. Features as small as a half-mile (1 kilometer) across are visible. picture site 'Amateur Astronomy' based upon a picture NASA/JHUAPL/SWRI |
 | A surface layer of exotic ices has flowed around obstacles and into depressions, much like glaciers on Earth as seen on that picture as a sheet of ice clearly appears to have flowed -and may still be flowing there. Sputnik Planum as a whole is constituting the largest known glacier in the solar system. picture site 'Amateur Astronomy' based upon a picture NASA/JHUAPL/SwRI |
 | Backlit by Sun, Pluto’s atmosphere displays its silhouette like a luminous halo in this image as New Horizons was speeding away from the planet. The image reveals layers of haze that are several times higher than scientists predicted. picture site 'Amateur Astronomy' based upon a picture NASA/JHUAPL/SwRI |
 | Hazes detected during the flyby are a key element in creating the complex hydrocarbon compounds that give Pluto’s surface its reddish hue. Models suggest the hazes form when ultraviolet sunlight breaks up methane gas particles which are a simple hydrocarbon in Pluto’s atmosphere. The breakdown of methane triggers the buildup of more complex hydrocarbon gases, such as ethylene and acetylene. As these hydrocarbons fall to the lower, colder parts of the atmosphere, they condense into ice particles, or tholings that create the hazes. picture site 'Amateur Astronomy' based upon a picture NASA |
 | New Horizons has found that Pluto’s atmosphere has an unexpectedly low surface pressure, at about half the value previously inferred from Earth-based, or 1/100-thousandth that of the pressure on the surface of Earth observations. Winds at Pluto thus should be mostly inexistant. Pluto's atmosphere had been decreasing since 3 decades. picture site 'Amateur Astronomy' based upon a picture NASA |
Mission's scientists found that Charon’s color palette is not as diverse as Pluto’s. Many expected Charon to be a monotonous, crater-battered world. They found instead a landscape covered with mountains, canyons, landslides, and more. The region informally called Sputnik Planum has been found to be rich in nitrogen, carbon monoxide and methane ices as some of the processes on Pluto appear to have occurred geologically recently, including those that involve the water-ice rich bedrock as well as the more volatile, and presumably more mobile, ices of the western lobe of Pluto’s 'heart.' Mysterious fault lines, generally, some hundred of miles (kilometers) long may suggest a hidden subsurface ocean. As far as Charon is concerned, only one crater is rich in frozen ammonia instead of ordinary water ice. The crater could be younger, or perhaps the impact that created it hit a pocket of ammonia-rich subsurface ice or the impactor brought its own ammonia. 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 based upon cold, ammonia-water magmas. First studies about Pluto resulting from the New Horizons data are like that craters count on Pluto have shown that some regions are dating to just after the formation of the planets in our solar system, about four billion years ago. The crater-free Pluto's 'heart,' on a other hand, formed within the past 10 million years only. Intermediate, midle-aged terrain completes the find. That wide range of surface ages likely means Pluto has been geologically active throughout its history. Images of Pluto’s four smallest satellites, on a other hand indicate several of them could be the results of mergers of two or more moons as Pluto had more moons in the past, in the aftermath of the big impact that also created Charon. Mountains, informally named Wright Mons and Piccard Mons, could be cryovolcanoes, which may have been active in the recent geological past. The two cryovolcano candidates are large features measuring tens of miles or kilometers across and several miles or kilometers high, large mountains with a large hole at their summit likely a result of material collapsing during a eruption and humocky texture on the flanks volcanic flows
 | As New Horizons was approaching Pluto, the mission captured images of Pluto (left) and Charon (right) rotating over the course of one day. Those images are showing the differences between the 'encounter hemisphere' and the so-called 'far side.' Pluto and Charon are rotating once 6.4 Earth days. picture site 'Amateur Astronomy' based upon pictures NASA |
 | That view of Charon taken July 13, 2015, from a distance of 289,000 miles (466,000 kilometers), combined with color information, is showing that the marking in the Moon’s north polar region appears to be a thin deposit of dark material over a distinct, sharply bounded, angular feature. picture site 'Amateur Astronomy' based upon a picture NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute |
 | Charon is home to an unusual canyon system, informally naed Argo Chasma, with a total length approximately 430 miles (700 kilometers) and a depth estimated at 5.5 miles (9 kilometers). picture site 'Amateur Astronomy' based upon a picture NASA/JHUAPL/SwRI |
 | This synthetic perspective view of Pluto, based on the latest high-resolution images downlinked by mid-September 2015, is a wiew if you were approximately 1,100 miles (1,800 km) 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 image was taken as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 km). picture site 'Amateur Astronomy' based upon a picture NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute |
 | Pluto is showing a diversity of landforms and complexity of processes, like 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 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. The view here is showing dunes. picture site 'Amateur Astronomy' based upon a picture NASA |
 | 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 110 miles (170 kilometers). picture site 'Amateur Astronomy' based upon a picture NASA/JHUAPL/SwRI |
 | 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 that stunning view. It is a near-sunset view with rugged, icy mountains and flat ice plains extending to Pluto’s horizon as Sputnik Planum (right) is flanked to the West (left) by rugged mountains up to 11,000-foot (3,500 meters) high. The backlighting also highlights more than a dozen layers of haze in Pluto’s tenuous atmosphere. The image was taken from a distance of 11,000 miles (18,000 kilometers) to Pluto as the scene is 230 miles (380 kilometers) across. picture site 'Amateur Astronomy' based upon a picture NASA/JHUAPL/SwRI |
 | Pluto’s crescent was taken on July 14 and offers a oblique look across Plutonian landscapes with dramatic backlighting from the Sun! This a enlarged view of the previous, at 780 miles (1,250 kilometers) across. picture site 'Amateur Astronomy' based upon a picture NASA |
 | Tartarus Dorsa, rises up along Pluto’s day-night terminator and shows intricate but puzzling patterns of ridges and material in between. The jagged geological ridges found at the highest altitudes on Pluto’s surface, near its equator, and soaring many hundreds of feet into the sky are due to methane freezing out of the atmosphere. That is further due, generally to Pluto undergoing climate variation on a scale of millions of years as, when warmer, the methane ice sublimate. Such a phenomenon is also seen at Earth with 'penitentes' seen at high altitude close to the equator. This view, roughly 330 miles (530 kilometers) across, was turned by us into a natural color view. Taken during the closest of the July 14 flyby, it show details as small as 0.8 miles (1.3 kilometers). picture site 'Amateur Astronomy' based upon a picture NASA/JHUAPL/SWRI |
 | That global, most detailed view of Pluto, turned into natural color view by us hints to a complex geological and climatological story at the dwarf planet. picture site 'Amateur Astronomy' based upon a picture NASA |
 | A high-resolution swath across -the highest-resolution yet available of Pluto- reveals features that transition from a mountainous region to a area of dunes and isolated peaks. Pluto might hold methane dunes, which is amazing as the atmosphere's feeble pressure at Pluto yields weak winds only. The process of sublimation however where ice turns straight into gas, without going through the liquid phase, also lifts particles and could dislodge the sediment carried by winds to form these methane rich dunes. Turned into a natural color view by us. picture site 'Amateur Astronomy' based upon a picture NASA |
 | A map of methane ice across part of Pluto's surface 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. Higher concentrations on bright plains and crater rims exists, but usually none in the centers of craters or darker regions. picture site 'Amateur Astronomy' based upon a picture NASA |
 | Styx, Pluto’s smallest moon, which had been discovered by the Hubble Space Telescope in 2012 is seen here from 391,000 miles (631,000 kilometers). Styx looks like a highly-elongated satellite, roughly 4.5 miles (7 kilometers) across in its longest dimension and 3 miles (5 kilometers) in its shortest, and maybe a highly reflective, icy surface, similar to what was previously found for two of Pluto’s other small moons, Nix and Hydra. picture site 'Amateur Astronomy' based upon a picture NASA/JHUAPL/SwRI |
 | Pluto’s 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 (nitrogen and methane molecules react with one another to form more and more complex negatively and positively charged ions. When they recombine, they form very complex macromolecules. 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). Picture is in natural colors and reveals the haze is blue, thus yielding a blue sky at Pluto! The haze particles themselves are likely gray or red as they scatter blue light. Scattering on Earth is due to tiny nitrogen molecules. picture site 'Amateur Astronomy' based upon a picture NASA/JHUAPL/SwRI |
 | New Horizons has detected numerous small, exposed regions of water ice on Pluto, which are highlighted in blue in this composite image. Strongest signatures are seen at some places as smaller outcrops looks like they are mostly associated with impact craters and valleys between mountains. Large expanses of Pluto, at the contrary, don’t feature such exposed water ice because it is masked by more volatile ices. Places with the most water ice are those with brighter red (matching tholins at the surface) in color images of Pluto. The scene is approximately 280 miles (450 kilometers) across. picture site 'Amateur Astronomy' based upon a picture NASA/JHUAPL/SwRI |
 | On that 130-mile (210-km) wide scene, with North to the upper left, are seen plains’ enigmatic cellular pattern (left) as well as unusual clusters of small pits and troughs (from lower left to upper right). On such plains of volatile ices such a solid nitrogen, it is theorized that pits and troughs –typically hundreds of yards (meters) across and tens of yards (meters) deep– are possibly formed by sublimation or evaporation of these ices. However, the reasons for the striking shapes and alignments of these features are a mystery, and maybe hint to a certain flow. With no impact craters that region seems extremely geologically young. picture site 'Amateur Astronomy' based upon a picture NASA/JHUAPL/SwRI |
 | That landscape is showing a plain at Charon with rilles and intermittently spaced impact craters, highlighting a landscape reminiscent of Earth’s Moon lunar mare. However, while the lunar maria are made of basalt, these plains on Charon consist of water ice. picture site 'Amateur Astronomy' based upon a picture NASA/JHUAPL/SwRI |
 | Pluto's diminutive moon Kerberos appears to be smaller than scientists expected and has a highly-reflective surface, counter to predictions prior to the Pluto flyby in July. 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. 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. picture site 'Amateur Astronomy' based upon a picture NASA |
 | Family Portrait of Pluto’s Moons with that composite image showing a sliver of Pluto’s large moon, Charon (bottom), and all four of Pluto’s small moons. 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. picture site 'Amateur Astronomy' based upon a picture NASA/JHUAPL/SwRI |
 | That image strip, 50 miles (80 kilometers) wide with resolutions of about 250-280 feet (77-85 meters) per pixel, is the first in a series of the sharpest views of Pluto it obtained during its 2015 July flyby -and the best close-ups of Pluto that humans may see for decade. The strip goes from the planet's limb to the icy plains, including a wide variety of cratered, mountainous and glacial terrain. In details, impact craters, North, are seen with layering as mountains, South, might be huge ice blocks that have been jostled and tumbled and somehow transported to their present locations. The insert at the upper right is showing the strip in context as the global image was colorized by us. picture site 'Amateur Astronomy' based upon a picture NASA/JHUAPL/SwRI |
 | Here is the highest resolution image ever obtained of the intricate pattern of pits at Pluto. Mission scientists believe these mysterious indentations may form through a combination of ice fracturing and evaporation. The scarcity of overlying impact craters in this area also leads scientists to conclude that these pits -typically hundreds of yards (meters) across and tens of yards (idem) deep- formed relatively recently (picture colorized by us). picture site 'Amateur Astronomy' based upon a picture NASA/JHUAPL/SwRI |
 | This high-resolution swath of Pluto sweeps across cratered plains and numerous prominent faults West of New Horizons’ encounter hemisphere. It also skims the eastern margin of a dark, forbidding region and finally passes over the mysterious, possibly cryovolcanic edifice 'Wright Mons,' before reaching the terminator or day-night line. Details as small as 500 yards (500 meters) can be seen. Bright methane ices condense on many crater rims, as dark red tholins (small soot-like particles generated from reactions involving methane and nitrogen in the atmosphere) are seen in low areas, like the bottoms of craters. Tholins in some place seem to have flowed as deposits of that thickness aren’t usually mobile on large scales, suggesting that they might be riding along with ice flowing underneath, or being blown around by Pluto’s winds (picture colorized by us as the area may be localized with the insert at top left). picture site 'Amateur Astronomy' based upon a picture NASA/JHUAPL/SwRI |
 | Those vast stretches of Pluto, informally named Sputnik Planum, are at a lower elevation than most of the surrounding area by a couple of miles. Their surface is separated into cells or polygons 10 to 25 miles wide, and when viewed at low sun angles (with visible shadows), the cells are seen to have slightly raised centers and ridged margins, with about 100 yards of overall height variation. Scientists believe the pattern of the cells stems from the slow thermal convection of the nitrogen-dominated ices that fill the plains of Pluto. A reservoir that’s likely several miles deep in some places, the solid nitrogen is warmed at depth by Pluto’s modest internal heat, becomes buoyant and rises up in great blobs, and then cools off and sinks again to renew the cycle, a kind of process akin to a lava lamp large like the Hudson Bay. Such blobs of overturning solid nitrogen can slowly evolve and merge over millions of years. The ridged margins, which mark where cooled nitrogen ice sinks back down, can be pinched off and abandoned (picture colorized by us as the area may be localized with the insert at top left). Centers of cells at Pluto's glacial plains tend to be smoother, while their edges rougher and more pitted. The boundaries between ice cells are even smoother than the cell centers as such a pattern is very likely a consequence of the convective flow within the nitrogen ice of Sputnik Planum. Warmer ice rises at the centers of cells, travels outward, and descends at the edges. As smooth plains are occasionally seen to stretch across cell boundaries, that may indicate that the convective system is unstable and constantly evolving, with cells likely splitting apart and recombining. picture site 'Amateur Astronomy' based upon a picture NASA/JHUAPL/SwRI |
 | That picture is showing Wright Mons, one of two potential cryovolcanoes at Pluto. Features as small as 1,500 feet (450 meters) across are seen as the entire scene is 140 miles (230 kilometers) across. At about 90 miles (150 kilometers) across and 2,5 miles (4 kilometers) high, only one impact crater is seen in the area, hinting to a very young age of that feature or to a recent activity of a ice volcano (the insert, top right, is showing the position of the area at Pluto). If a volcano Wright Mons would be the largest such feature discovered in the outer solar system. picture site 'Amateur Astronomy' based upon a picture NASA/JHUAPL/SwRI |
 | This processed image is the highest-resolution color look yet at the haze layers in Pluto’s atmosphere. Pluto’s atmosphere is blue. Shown in approximate true colors it has a resolution is 0,6 miles (1 kilometer) per pixel. Scientists believe the haze is a photochemical smog resulting from the action of sunlight on methane and other molecules in Pluto’s atmosphere, producing a complex mixture of hydrocarbons such as acetylene and ethylene, accumulating into small particles, a fraction of a micrometer in size, and scatter sunlight to make the bright blue haze seen in this image. As they settle down through the atmosphere, the haze particles form numerous intricate, horizontal layers, some extending for hundreds of miles around Pluto. The haze layers, generally, extend to altitudes of over 120 miles (200 kilometers). Surface features may be seen just within the limb to the right. Pluto's atmosphere is predominantly nitrogen gas, along with small amounts of methane and carbon monoxide. Haze particles form high up in the atmosphere, more than 20 miles above the surface as methane and other gases react to sunlight, before slowly raining down to the icy surface. The thin haze enshrouding Pluto is made of very small particles that remain in the atmosphere for prolonged periods of time rather than immediately falling to the surface. Haze particles are also actively being replenished. The particles are extremely small, just 0.06-0.10 microns thick as they scatter blue light more than other colors as they drift toward the surface, creating the haze's blue tint. That has a consequence about Pluto atmosphere's fate as Pluto is now heading away from the Sun on its orbit. Some thought that less surface ice would be vaporized -- creating fewer atmospheric gases while losses to space continued -- eventually leading to atmospheric collapse. But rather than collapsing, the atmosphere appears to change on a shorter cyclical pattern due to the size of the particles. The haze on the other hand, thickens and then fades in a cycle lasting just a few years with the tiny particles being created relatively quickly. Pluto's elliptical, and inclined orbit and the planet's much inclined poles axis, causes some areas of the dwarf planet to be exposed to more sunlight at different points in the orbit. When ice-rich regions are exposed to sunlight, the atmosphere may expand and create more haze particles, but as those areas receive less sunlight, it may shrink and become clearer. This cycle has continued even as Pluto's distance from the Sun has increased, though it's not clear if this pattern will continue. picture site 'Amateur Astronomy' based upon a picture NASA |
Finds presented by late 2015 are showing that Pluto is a world with a widespread past and present glacial activity, including the formation of networks of eroded valleys, some of which are 'hanging valleys' like these seen at Earth. Mission scientists have determined that key to understanding activity on Pluto is the role of a deep layer of solid nitrogen and other volatile ices that fill the left side of Pluto’s so-called 'heart,' that 620-mile (1,000-kilometer)-wide basin. New numerical models of thermal convection within this ice layer not only explain the numerous polygonal ice features seen but also, they indicate this layer may be up to a few miles (kilometers) thick. Evaporation of this nitrogen and condensation on higher surrounding terrain leads to glacial flow back toward the basin. Additional numerical models of nitrogen ice flow show how Plutonian landscapes were and are still being transformed. New Horizons has found new and more stringent limits for a atmosphere on Pluto’s largest moon, Charon as ammonia (NH3) exists across a large portion of Charon's surface with some high local concentrations. Organa Crater, for example, has been noted as being especially rich in NH3 as what controls the distribution of Charon’s NH3 is still unknown. Pluto and its moons, further, interact with the solar wind, which is still flowing at 900,000 miles per hour (1.4 million kilometers per hour) at Pluto as the planet's escaping atmosphere provides a source of neutral atoms that can exchange electrons with its positively charged atoms of oxygen (O), carbon (C), and nitrogen (N)
 | This image is showing Pluto’s atmosphere in infrared wavelengths as sunlight is coming from above and behind Pluto. North is around the 10 o’clock position. The blue ring around Pluto is caused by sunlight scattering from haze particles common in Pluto's atmosphere; scientists believe the haze is a photochemical smog resulting from the action of sunlight on methane and other molecules, producing a complex mixture of hydrocarbons such as acetylene and ethylene. These hydrocarbons accumulate into small particles –a fraction of a micrometer in size– which scatter sunlight to make the blue haze. That image gives scientists new clues into the size distribution of the particles. The whitish patches around Pluto’s limb in this image are sunlight bouncing off more reflective or smoother areas on Pluto's surface –with the largest patch being the western section of the informally named Cthulhu Regio. Future observational data returned should capture the remainder of the haze, missing from the lower section of the image. picture NASA |
 | That false-color picture points to more prevalent water ice on Pluto’s surface than previously thought. Two scans were stitched into a combined multispectral Pluto 'data cube, or a three-dimensional array in which a image of Pluto is formed at each wavelength considered, covering the full hemisphere visible to New Horizons as it flew past Pluto and based upon model map ices of Pluto. Water ice is Pluto's crustal 'bedrock,' the canvas on which its more volatile ices are lying and seasonally changing. No water means that Pluto's icy bedrock is well hidden beneath a thick blanket of other ices such as methane, nitrogen and carbon monoxide. picture NASA |
 | Nitrogen ice glaciers on Pluto once flowed into the plains, appear to carry an intriguing cargo like numerous, isolated hills that may be fragments of water ice from the uplands, with one to several miles (kilometers) across. Such hills are likely miniature versions and even broken fragments, of the larger, jumbled mountains the western border of the area informally named Sputnik Planum. Because water ice is less dense than nitrogen-dominated ice, scientists believe these water ice hills are floating in a sea of frozen nitrogen. Chains are also seen along the glaciers' flow path as, when they reach the convective areas, hills are pushed to the edges of the cells, in groups reaching up to 12 miles (20 kilometers) across. At the northern end of the image a feature appears to be an especially large accumulation of these hills, measuring 37 by 22 miles (60 by 35 kilometers), near the boundary with the uplands. picture NASA |
 | To make sense of Pluto’s surprising geological complexity, New Horizons mission scientists construct geological maps like the one shown here, covering 1,290 miles (2,070 kilometers) from top to bottom, and including Sputnik Planum. Each terrain, or unit, is defined by its texture and morphology. picture NASA/JHUAPL/SwRI |
 | As Charon's surface is characterized by a system of 'pull-apart' tectonic faults under the forms of ridges, scarps and valleys, and the outer layer of Charon primarily water ice, it was evidenced that layer was kept warm when Charon was young by heat provided by the decay of radioactive elements, as well as Charon’s own internal heat of formation. Such that heat could have caused water ice to melt deep down, creating a subsurface ocean. When Charon cooled over time, that ocean would have frozen and expanded, lifting the outermost layers of the moon and producing a vast equatorial belt of chasms we see today, one of the longest seen anywhere in the solar system, at least 1,100-mile (about 1,800 kilometers) long and 4.5-mile (7.5-kilometer) deep. picture NASA/JHUAPL/SwRI |
 | A large frozen canyon, about 45-mile (75-kilometer) wide, running close to Pluto's North Pole, is seen left on that image. All the canyons seen here appear to be degraded in terms of walls as they appear to be much older than the more sharply defined canyon systems elsewhere on Pluto. They also appear to represent evidence for an ancient period of tectonics. Large, irregularly-shaped pits which may reach 45-mile (70-kilometer) across and 2.5-mile (4-kilometer) deep, are scarring the region. Methane ice is abundant across the area, and there is relatively little nitrogen ice. The lower edge of the image measures about 750-mile (1,200-kilometer) long. picture site 'Amateur Astronomy' based upon a picture NASA |
 | Six extensional fractures which can reach hundreds of miles long, are converging to a point, as they noticeably expose red deposits below the surface. The fractures area is intercepting Pluto's bladed terrain South. The image is in enhanced colors. As fractures elsewhere are due to the expansional move of Pluto's crust, that peculiar radiating feature might be similar to radially fractured centers on Venus called novae or the Pantheon Fossae formation at Mercury and due to a focused source of stress under the crust at that point. picture site 'Amateur Astronomy' based upon a picture NASA/JHUAPL/SwRI |
Exotic snowcapped mountains located at Pluto's dark area covered of dark tholins are coated with a bright material which could be predominantly methane that has condensed as ice onto the peaks from Pluto's atmosphere. Methane ice might act like water in Earth's atmosphere. A process known as sublimation—the transition of a substance from a solid to a gas might have the methane ice-rich surface on Pluto may be sublimating away into the atmosphere, exposing a layer of water-ice underneath. Surface expressions and geology at Pluto are raising fundamental questions about how small planets can have active processes billions of years after they formed. Numerous haze layers seen at Pluton typically extend horizontally over hundreds of kilometers, but are not strictly parallel to the surface. The Plutonian atmosphere is at about -203°C, just 70 degrees above absolute zero, which likely put a brake upon how it escapes to space, at a pace not larger than what happens at Earth. The atmosphere is composed mostly of nitrogen, with smaller amounts of compounds such as methane (the latter the main component escaping). High in the atmosphere -- between 310 and 620 miles (500 and 1,000 kilometres) above -- sunlight triggers chemical reactions that transform some of these gases into solid hydrocarbon particles. Those drift downwards and they eventually form, with other particles thick layers of haze at 120 miles (200km). Papers by March 2016 term Pluto a real world with diverse and active geology, exotic surface chemistry, a complex atmosphere, puzzling interaction with the Sun and a intriguing system of small moons. The diversity of the planet's landscape stems from eons of interaction -with likely cycles of evaporation and condensation- between highly volatile and mobile methane, nitrogen and carbon monoxide ices with inert and sturdy water ice. Pluto's 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. Evidence was found that some of the moons resulted from mergers of even smaller bodies, and that their surface ages date back at least 4 billion years. It might that moons formed in the aftermath of a collision that produced the Pluto-Charon binary system. Methane clathrate (a clathrate is a structure in which a primary molecular species (say water, or H2O) forms a crystalline ‘cage’ to contain a guest molecule (methane or CH4, for example)) might provide for some structures with sharp walls as observed in some regions. Methane clathrates in the icy moons of the outer solar system and also in the Kuiper Belt were formed way back before the solar system formed, within the protosolar nebula. Features in Tartarus Dorsa reach hundreds of feet high and are typically spaced a few miles apart. This remarkable landform, unlike any other seen in our solar system, is perched on a much broader set of rounded ridges that are separated by flat valley floors. Current theories providing a explanation include erosion from evaporating ices or deposition of methane ices
Millions or billions of years ago, thanks to much higher pressure in Pluto’s atmosphere and warmer conditions on the surface, liquids might have flowed across and pooled on the surface of the distant world. A frozen lake of liquid nitrogen has been spotted and also channels that may also have carried liquids. Right now, Pluto is between two extreme long-term climate states as the planet has both 'Tropics' and a arctic region. Pluto's long-term polar axis shifts also drive sharp changes in the planet's atmospheric pressure over time, possibly causing Pluto’s atmosphere to be much more massive than that of even Mars, and with the possibility that liquid nitrogen may have once or even many times flowed at Pluto. In terms of the miscellaneous glacial landscapes seen at the faraway world, two scenerios are possible: the erosion could be gradual, when much of Pluto’s nitrogen ice was lost over time. Or, it could be part of a cycle in which the nitrogen ice evaporates and redeposits on the highlands, before flowing back into the plains. In all likelihood, both scenarios have been and still are operating. The giant impact believed to have created all of Pluto's known satellites, as far as it is concerned, cannot be recent and instead occurred some 4 billion years ago. Mission scientists have discovered that the layers of haze in Pluto’s nitrogen atmosphere vary in brightness depending on illumination and viewpoint, yet the overall vertical structure and height above the surface is preserved. That might be due to 'gravity waves' yielded when air flow over mountain ranges. The brightness in the layers has been seen varying by about 30 percent
 | Eye-catching craters looking like a cluster of bright halos scattered across a dark landscape are said 'haloed' craters. The largest of these, bottom-right, measures about 30 miles (50 kilometers) across. The craters' bright walls and rims stand out from their dark floors and surrounding terrain, creating the halo effect. A connection in the lower image is established between the bright halos and distribution of methane ice, shown as purple as the floors and terrain between craters show signs of water ice, colored in blue. Exactly why the bright methane ice settles on these crater rims and walls is a mystery; also puzzling is why this same effect doesn’t occur broadly across Pluto. picture site 'Amateur Astronomy' based upon a picture NASA/JHUAPL/SwRI |
 | The vast expanse of the icy surface informally named Sputnik Planum at Pluto is on average 2 miles (3 kilometers) lower than the surrounding terrain in that shaded relief view. Angular blocks of water ice along the western edge of Sputnik Planum are floating upon the bright deposits of softer, denser solid nitrogen. Topographic maps of Pluto are produced from digital analysis images acquired during the flyby, as they are derived from digital stereo-image mapping tools that measure the parallax -or the difference in the apparent relative positions- of individual features on the surface obtained at different times. Parallax displacements of high and low features are then used to directly estimate feature heights. picture NASA |
Pluto is more like a planet like Mars or Venus in the way it interacts with the solar wind as, until now, most researchers thought the faraway world was characterized more like a comet, which had a large region of gentle slowing of the solar wind, as opposed to the abrupt diversion solar wind encounters at a planet. Pluto might better be hybrid. Like Earth, Pluto has a long ion tail, that extends downwind at least a distance of about 100 Pluto radii loaded with heavy ions from the atmosphere and with considerable structure as Pluto’s obstruction of the solar wind upwind of the planet is smaller than thought, at about the distance of a couple planetary radii (1,844 miles/3,000 kilometers). Pluto has a very thin boundary of its tail of heavy ions and the sheath of the shocked solar wind that presents an obstacle to its flow. A study of Pluto's atmosphere during a star occulation has shown that the upper atmospheric temperature is as much as 25 percent colder and thus more compact than predicted, and the escape rate of nitrogen is about 1,000 times lower than expected. The upper atmosphere vertical profiles of nitrogen and methane, and the observed hydrocarbons, on a other hand, are similar over many locations on Pluto. Cells 10 to 30 miles (16 to 48 kilometers) across, and less than one million years old at Pluto’s icy surface are being constantly renewed by a process called convection that replace older surface ices with fresher material. A reservoir that’s likely several miles deep in some places has the solid nitrogen warmed by Pluto’s modest internal heat, turned buoyant and risen up in great blobs before cooling off and sinking again to renew the cycle over millions of years. Cells' ridges mark where cooled nitrogen ice sinks back down can be pinched off and abandoned. Pluto's surface in such a area is renewed every 500,000 years or so. Such a activity also probably helps support Pluto’s atmosphere by continually refreshing the surface. That also proves that even on a cold planet there is sufficient energy for vigorous geological activity
 | That image of Pluto’s informally named Venera Terra region is showing a expanse of terrain described by mission's scientists like 'fretted.' That terrain consists of bright plains divided into polygon-shaped blocks by a network of dark, connected valleys typically reaching a few miles (3 to 4 kilometers) wide. Numerous impact craters of up to 15 miles (25 kilometers) in diameter also dot the area, implying the surface formed early in Pluto’s history. No such terrain is seen elsewhere at Pluto as it is also a rare type in the solar system. The well-known example of such being Noctis Labyrinthus on Mars. The distinct interconnected valley network was likely formed by extensional fracturing of Pluto’s surface. The valleys separating the blocks may then have been widened by movement of nitrogen ice glaciers, or flowing liquids, or possibly by ice sublimation at the block margins. The blocks are rich in methane ice as methane is susceptible to sublimation at Pluto surface conditions. The resolution of the image is approximately 2,230 feet (680 meters) per pixel. picture NASA/JHUAPL/SwRI |
 | Those dark, rugged highlands informally known as Krun Macula (lower right), bordering South large Pluto’s Sputnik Planum, are siding deep valleys formed by assembling pits, more than 25 miles (40 kilometers) long, 12.5 miles (20 kilometers) wide and almost 2 miles (3 kilometers) deep and have floors covered with nitrogen ice. Whether such relief formed from collapse, or a other way, remains a mystery. picture NASA/JHUAPL/SwRI |
 | New Horizons instruments data helped produce these compositional maps which indicate regions of Pluton rich in ices of methane (CH4), nitrogen (N2) and carbon monoxide (CO), or water ice (H2O). picture NASA |
 | That area South of Pluto’s dark equatorial band is showing a chain of methane-snowcapped bright mountains. Methane has condensed as frost onto these surfaces at high elevation. Valleys between some mountains are each a few miles (kilometers) across and tens of miles (idem) long. A other valley system in the expansive plains might be linked to a surface collapse marking the end of when the ice in Sputnik Planum was at a higher elevation. picture NASA/JHUAPL/SwRI |
Scientists have learned that reddish material in the north polar region of Charon during the long Plutonian winter -- which also seen like a dark region on black & white pictures -- is chemically processed methane that escaped from Pluto’s atmosphere and freezed (or bouncing back into space). Even when the Sun is -- rarely -- reaching there, the methane ice quickly sublimates away but the heavier hydrocarbons created from it by the solar ultraviolet remain on the surface, and sunlight further irradiates those leftovers into that reddish material –- called tholins -– that has slowly accumulated on both Charon’s poles over millions of years. Low-energy X-rays from Pluto have been detected from NASA’s Chandra X-ray space observatory at Earth. That emission remains a mystery however because Pluto is cold, rocky and without a magnetosphere, thence it features no natural mechanism for emitting X-rays. Like with a comet, on a other hand, Pluto's interaction with the solar wind can yield X-rays but Pluto’s interaction with the solar wind is much more like the interaction of the solar wind with Mars, than with a comet. Pluto, at last, contains a very mild, close-in bowshock, where the solar wind first meets Pluto and a small wake or tail behind the planet. Pluto’s present, hazy atmosphere is almost entirely free of clouds, though scientists from NASA’s New Horizons mission have identified some cloud candidates after examining images. All are low-lying, isolated small features as they might be suggestive of possible, rare condensation clouds. Brightest areas at Pluto's surface, generally, are among the most reflective in the solar system, a hint of surface activity. Landslides are the only type of geological activity is missing at Pluto (they exist however at Charon). Sputnik Planitia -- which turned the official name to Sputnik Planum is made mostly of nitrogen ice, churning and flowing in massive glaciers, and, with its sheer size of 622 miles (1,000 kilometres) across and at least several miles (kilometres) deep, it exerts extraordinary influence over Pluto's behaviour. The area might even have altered the planet's tilt as it might be a crater punched by a giant Kuiper Belt object impact, which later filled with ice, the mass of which caused a rotation relative to the spin axis. Such a gravitational anomaly further could have been yielded by a subterranean ocean of water-ice that at least viscous. Sputnik Planitia might have also accumulated ice without an impact as the mass depressed the ground beneath it. The nitrogen ice cap could have also formed early on, when Pluto was still spinning quickly, and did not necessarily require an impact basin as the climate then was forced by the 120 degree tilt of Pluto’s spin axis and the latitudes near 30 degrees north and south emerged as the coldest places. A small ice deposit further naturally attracts more ices by reflecting solar light and heat, or the 'runaway albedo' effect as Sputnik Planitia sank into the terrain and is now lower than the surrounding terrain. A refinement to the impact theory, on a other hand, is that the Sputnik Planitia basin formed and migrated to its present location after Pluto slowed its rotation, for cause of extra mass (a slow refreezing of a subterranean ocean could also explain the network of fractures seen on Pluto’s surface). Sputnik Planitia also participates --with the surface of the planet, generally -- into Pluto's atmosphere, with nitrogen, methane and CO2 sublimating, or condensing back function of temperature of Pluto along its orbit. Such a move also occur every day. The sublimation is reaching to the highest altitudes in the atmosphere where photochemical reactions create new carbon and nitrogen compounds which form layered hazes that extend more than 124 miles (200 kilometres) above the surface. There, particles cannot condense out directly for cause to the temperatures too warm and they do on the basis of dust raining in from interplanetary space maybe serving as nuclei. New compounds thence drift down, clumping, growing bigger and more rounded. Methane and nitrogen ices co-exist in a mix where one substance or the other dominates, function of where the surface is located at Pluto; nitrogen rules at Sputnik Planitia as further North, about 55 degrees latitude, constant summer sunlight since 20 years seems to have stripped most of the nitrogen away
 | A graphic view of the Pluto-solar wind interaction. picture NASA |
As the last data were transmitted from New Horizons by early November 2016, first synthesis may be found allowing to more general or detailed view
Features, known as 'penitentes,' or bowl-shaped depressions with blade-like spires around the edge that rise several hundreds of feet are due to erosion and evaporating ice. Such ridges are more than 1,600 feet (about 500 meters) tall and separated by two to three miles (about three to five kilometers). The environment at Pluto is cold, the air thin, the Sun very dim and snow and ice made from methane and nitrogen instead of water. Pluto’s equator is mostly characterized by a band of dark red terrains
Since September 2017, the International Astronomical Union (IAU) began to officially name Pluto's relief features, from names proposed by the New Horizon team and the general public. Pluto's 'heart,' for example now bears the name of pioneering American astronomer Clyde Tombaugh, who discovered Pluto in 1930 or a crater is now officially named after Venetia Burney, the British schoolgirl who suggested the name 'Pluto,' for the newly-discovered planet
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