total descendants::0 total children::0 |
http://hirise.lpl.arizona.edu/PSP_007962_2635 "There is a vast region of sand dunes at high northern latitudes on Mars. In the winter, a layer of carbon dioxide ice covers the dunes, and in the spring as the sun warms the ice it evaporates. This is a very active process, and sand dislodged from the crests of the dunes cascades down, forming dark streaks." |
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