MAWRTH VALLIS, MARS - 20 December 2021 - Billions of years ago, a river flowed across this scene in Mawrth Vallis on Mars. Like on Earth, these river

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MAWRTH VALLIS, MARS - 20 December 2021 - Billions of years ago, a river flowed across this scene in Mawrth Vallis on Mars. Like on Earth, these river beds can get filled up with rocks that are cemented together. After Mars became a colder, drier place and the river disappeared, the rocky river bed remained. In this HiRISE image, we see a dark ridge snaking across the surface. The dark ridge is the old river bed. It is raised above its surroundings now because these softer surroundings have been eroded away, whereas the rocky river bed resists that. Scientists call these ridges inverted channels and many of them are visible in this area of Mars - Photo: Geopix/NASA/JPL-Caltech/University of Arizona

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Size: 3600px × 2250px
Location: Mawrth Vallis, Mars
Photo credit: © Geopix / Alamy / Afripics
License: Licensed
Model Released: No

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