This enhanced-color image shows sand dunes trapped in an impact crater in Noachis Terra, Mars. Dunes and sand ripples of various shapes and sizes display the natural beauty created by physical processes. The area covered in the image is about six-tenths of a mile (1 kilometer) across.
Sand dunes are among the most widespread wind-formed features on Mars. Their distribution and shapes are affected by changes in wind direction and wind strength. Patterns of dune erosion and deposition provide insight into the sedimentary history of the surrounding terrain.
The image is one product from an observation by the High Resolution Imaging Science Experiment (HiRISE) camera taken on November 29, 2011, at 42 degrees south latitude, 42 degrees east longitude. Other image products from the same observation are at http://www.uahirise.org/ESP_025042_1375.
Photo credit: NASA/JPL-Caltech/University of Arizona
Note: This caption is very similar to that of the recent post, Sand Dunes in Noachis Terra. Although the pictures are different, I wouldn't be surprised if both images come from the same crater.