“Possible Signs of Ancient Drying in Martian Rock” was uploaded to Flickr

A grid of small polygons on the Martian rock surface near the right edge of this view may have originated as cracks in drying mud more than 3 billion years ago. via NASA ift.tt/2jzvy1d
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Possible Signs of Ancient Drying in Martian Rock was taken on January 13, 2017 at 11:03AM