Craters trap wind-blown sand very effectively. In the Southern hemisphere we see fields of sand dunes on the floors of many craters.

Longitudinal dunes cross a portion of the floor of this un-named Southern hemisphere crater. Dust devil tracks that criss-cross the dunes remove a light layer of dust but do not disturb the ripples on the dunes. In the subimage large boulders appear partially buried by the drifting sand.

Written by: Candy Hansen   (23 March 2011)

More info and image formats at http://hirise.lpl.arizona.edu/ESP_021641_1205

Image: NASA/JPL/University of Arizona