View of Sputnik Planum. Credit: NASA/JHU APL/SwRI

A newly received image of Pluto reveals a sprawling icy plain of irregular, polygonal shapes ringed by hills and troughs. The apparent lack of craters in what is now called Sputnik Planum indicates that the region is still young by geological standards, scientists said Friday. They spoke at a briefing at NASA headquarters in Washington, D. C., about the latest images from the New Horizons mission.

“Judging from impact craters, it’s clear that Sputnik Planum couldn’t be more than 100 million years old” and may still be geologically active, said Jeff Moore, leader of the mission’s geology, geophysics, and imaging team at NASA’s Ames Research Center in Moffett Field, Calif.

Soaring mountains of ice, identified in an image of Pluto released on Wednesday and lying south of Sputnik Planum, indicate a similar maximum age for the dwarf planet’s apparently youthful surface, mission scientists said.

Moore’s team has two theories for how Sputnik Planum’s polygonal segments formed: They may result either from contraction of surface materials or from convection within a surface layer of frozen compounds, including carbon monoxide, methane, and nitrogen, driven by the little warmth within Pluto’s interior.

The new close-up of the Plutonian surface also shows hills, pitted surfaces, and dark material within the troughs.

“I may be a little biased, but I think the solar system saved the best for last,” said Alan Stern, principal investigator of the New Horizons mission, exulting over the newest views of the last of the solar system’s major bodies to be explored. Stern noted that the mission plans to release fresh images every week in the coming months.

The New Horizons spacecraft took this image of the curiously crater-free plain on Tuesday while rocketing toward its historic flyby of Pluto. The mission’s Long-Range Reconnaissance Imager made the shot from a distance of 48,000 miles (77,000 kilometers).

—JoAnna Wendel, Staff Writer

Citation: Wendel, J. (2015), New Pluto image reveals young icy plain, Eos, 96, doi:10.1029/2015EO032945. Published on 17 July 2015.

Text © 2015. The authors. CC BY-NC 3.0
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