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Science and Space
Main Health and Human Body Earth Space Prehistoric World A-Z

Martian Crater

Dust avalanches typically a few hundred to a thousand meters long tumble toward the center of an impact crater on Mars. What sets them off? Some say a gust of wind, but some think trace amounts of water can play a role. Slope streaks are found only in areas where surface temperatures rise just above the freezing point of water; the increase of pressure when water vaporizes might trigger the slides.

Photograph courtesy MRSS and NASA/JPL