Valley Networks in the Ancient Martian Highlands

The valley networks on Mars are terrains eroded by flowing water billions of years ago.

In places where the bedrock is well exposed, we often see a variety of colors due to altered minerals and polygonal patterns perhaps due to wet, clay-rich deposits.

Written by: Alfred McEwen (audio: Tre Gibbs)   (18 May 2016)

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Image: NASA/JPL/University of Arizona