Sunday, December 6, 2015

New Horizons Returns the First of Its Very Best Images of Pluto

In this highest-resolution image from NASA’s New Horizons spacecraft, great blocks of Pluto’s water-ice crust appear jammed together in the informally named al-Idrisi mountains. Some mountain sides appear coated in dark material, while other sides are bright. Several sheer faces appear to show crustal layering, perhaps related to the layers seen in some of Pluto’s crater walls. Other materials appear crushed between the mountains, as if these great blocks of water ice, some standing as much as 1.5 miles high, were jostled back and forth. The mountains end abruptly at the shoreline of the informally named Sputnik Planum, where the soft, nitrogen-rich ices of the plain form a nearly level surface, broken only by the fine trace work of striking, cellular boundaries and the textured surface of the plain’s ices (which is possibly related to sunlight-driven ice sublimation). This view is about 50 miles wide. The top of the image is to Pluto’s northwest. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

NASA’s New Horizons spacecraft has sent back the first few of a series of the sharpest views of Pluto it obtained during its July flyby – and this image sequence forms the best close-ups of Pluto that humans may see for decades. Every week the piano-sized New Horizons spacecraft transmits data stored on its digital recorders from its flight through the Pluto system on July 14. These latest pictures are part of a sequence taken near New Horizons’ closest approach to Pluto, with resolutions of about 250-280 feet (77-85 meters) per pixel – revealing features less than half the size of a city block on the diverse surface of the distant planet. In these new images, New Horizons captured a wide variety of spectacular, cratered, mountainous and glacial terrains.

“These close-up images, showing the diversity of terrain on Pluto, demonstrate the power of our robotic planetary explorers to return intriguing data to scientists back here on planet Earth,” said John Grunsfeld, former astronaut and associate administrator for NASA’s Science Mission Directorate. “New Horizons thrilled us during the July flyby with the first close images of Pluto, and as the spacecraft transmits the treasure trove of images in its onboard memory back to us, we continue to be amazed by what we see.”

The images being released today form a strip 50 miles (80 kilometers) wide trending from Pluto’s jagged horizon about 500 miles (800 kilometers) northwest of the informally named Sputnik Planum, across the al-Idrisi mountains, onto the shoreline of Sputnik and then across its icy plains.

“These new images give us a breathtaking, super-high resolution window into Pluto’s geology,” said New Horizons Principal Investigator Alan Stern, of Southwest Research Institute (SwRI) in Boulder, Colorado. “Nothing of this quality was available for Venus or Mars until decades after their first flybys; yet at Pluto we’re there already – down among the craters, ice fields and mountains – less than five months after flyby! The science we can do with these images is simply unbelievable.”

A video made from these images reveals amazing details on a world 3 billion miles away – as do individual close-ups taken from the wider swath. The images are six times better than the resolution of the global Pluto map New Horizons obtained, and five times better than the best images of Pluto’s cousin Triton, Neptune’s large moon, obtained by Voyager 2 in 1989.

This highest-resolution image from NASA’s New Horizons spacecraft reveals new details of Pluto’s rugged, icy cratered plains. Notice the layering in the interior walls of many craters (the large crater at upper right is a good example) – layers in geology usually mean an important change in composition or event but at the moment New Horizons team members do not know if they are seeing local, regional or global layering. The darker crater in the lower center is apparently younger than the others, because dark material ejected from within – its “ejecta blanket” – have not been erased and can still be made out. The origin of the many dark linear features trending roughly vertically in the bottom half of the image is under debate, but may be tectonic. Most of the craters seen here lie within the 155-mile (250-kilometer)-wide Burney Basin, whose outer rim or ring forms the line of hills or low mountains at bottom. The basin is informally named after Venetia Burney, the English schoolgirl who first proposed the name “Pluto” for the newly discovered planet in 1930. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
This highest-resolution image from NASA’s New Horizons spacecraft reveals new details of Pluto’s rugged, icy cratered plains. Notice the layering in the interior walls of many craters (the large crater at upper right is a good example) – layers in geology usually mean an important change in composition or event but at the moment New Horizons team members do not know if they are seeing local, regional or global layering. The darker crater in the lower center is apparently younger than the others, because dark material ejected from within – its “ejecta blanket” – have not been erased and can still be made out. The origin of the many dark linear features trending roughly vertically in the bottom half of the image is under debate, but may be tectonic. Most of the craters seen here lie within the 155-mile (250-kilometer)-wide Burney Basin, whose outer rim or ring forms the line of hills or low mountains at bottom. The basin is informally named after Venetia Burney, the English schoolgirl who first proposed the name “Pluto” for the newly discovered planet in 1930. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

“Impact craters are nature's drill rigs, and the new, highest-resolution pictures of the bigger craters seem to show that Pluto's icy crust, at least in places, is distinctly layered,” said William McKinnon, deputy lead of the New Horizons Geology, Geophysics and Imaging team, from Washington University in St. Louis. “Looking into Pluto’s depths is also looking back into geologic time, which will help us piece together Pluto’s geological history.”

“The mountains bordering Sputnik Planum are absolutely stunning at this resolution” added New Horizons science team member John Spencer. “The new details revealed here, particularly the crumpled ridges in the rubbly material surrounding several of the mountains, reinforce our earlier impression that the mountains are huge ice blocks that have been jostled and tumbled and somehow transported to their present locations.”

These images were made with the telescopic Long Range Reconnaissance Imager (LORRI) aboard New Horizons, in a timespan of about a minute centered on 11:36 UT on July 14 – just about 15 minutes before New Horizons’ closest approach to Pluto – from a range of just 10,000 miles (17,000 kilometers). They were obtained with an unusual observing mode; instead of working in the usual “point and shoot,” LORRI snapped pictures every three seconds while the Ralph/Multispectral Visual Imaging Camera (MVIC) aboard New Horizons was scanning the surface. This mode requires unusually short exposures to avoid blurring the images.

Mission scientists expect more imagery from this set over the next several days, showing even more terrain at this highest resolution.

New Horizons, speeding through deep space at more than 32,000 miles per hour, is approximately 104 million miles (167 million kilometers) beyond Pluto and 3.2 billion miles (5.2 billion kilometers) from Earth. All spacecraft systems are healthy.

New Horizons is part of NASA’s New Frontiers Program, managed by the agency’s Marshall Space Flight Center in Huntsville, Alabama. The Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, designed, built, and operates the New Horizons spacecraft and manages the mission for NASA’s Science Mission Directorate. The Southwest Research Institute leads the mission and mission science, payload operations, and encounter science planning.

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