The more photos of Pluto fired back from NASA's New Horizons probe, the more the icy dwarf planet's geological makeup comes into focus. The latest snaps are the highest-resolution images gathered by the spacecraft during its July flyby, and in revealing craters, mountains and glaciers, may be the sharpest close-ups humans will lay eyes on for decades.

The new set of images were captured during New Horizons' closest flyby of Pluto from a distance of 10,000 mil (17,000 km) and show features less than half the size of a city block on its surface. With resolutions of around 250 to 280 ft (77 to 85 m), the images have been stitched together to paint a relatively detailed portrait of a 50 mi (80 km) wide expanse of jagged mountainous terrain and vast icy plains.

The composition begins with a bumpy horizon that then gives way to a relatively flat area increasingly littered with craters, leading up to the informally named al-Idrisi mountains. These jagged ice mountains then clash abruptly with the shoreline of Sputnik Planum, a craterless plain where NASA believes exotic nitrogen, carbon monoxide and methane ices once flowed, and may even still be flowing just like glaciers on Earth three billion miles away.

"These new images give us a breathtaking, super-high resolution window into Pluto's geology," says New Horizons Principal Investigator Alan Stern. "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, mountains and ice fields – less than five months after flyby! The science we can do with these images is simply unbelievable."

Like the other images returned from New Horizons in recent months, the images were taken by the spacecraft's Long Range Reconnaissance Imager (LORRI), though a slightly different technique was used. Rather than the typical point and shoot approach, LORRI was made to snap pictures every three seconds, while the craft's Ralph/Multispectral Visual Imaging Camera (MVIC) scanned the surface.

To avoid blurring, the images were taken at very short exposures, resulting in photos NASA says are of six times better resolution than the global map of Pluto produced in July, giving scientists new insights into the dwarf planet's unique features.

"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," says William McKinnon, deputy lead of the New Horizons Geology, Geophysics and Imaging team. "Looking into Pluto's depths is looking back into geologic time, which will help us piece together Pluto's geological history."

The animation below offers a flyover of the region observed in the images, while a large version of the composition can be viewed online here (be sure to zoom in).

Source: NASA

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