This large crescent dune in Kaiser Crater shows the scars of many types of seasonal erosional activities. Along its <a rel="nofollow" class="external text" href="http://static.uahirise.org/images/2017/details/cut/ESP_020876_1330.jpg">downwind slope are large gullies</a> which are active during winter, when frost drives dune material downslope, carving out channels and creating fan-shaped aprons.
<p>On the upwind slope (bottom), dust devil tracks are visible: dark lines and curliques created during the spring season by small wind vortices vacuuming up a thin layer of dust and exposing the dark dune sand.
</p><p>This is a stereo pair with <a rel="nofollow" class="external text" href="http://www.uahirise.org/ESP_021720_1330">ESP_021720_1330</a>.
</p><p>Note: Both the cutout and the above image are rotated so that North is to the right.
</p><p>The map is projected here at a scale of 25 centimeters (9.8 inches) per pixel. [The original image scale is 25.3 centimeters (10 inches) per pixel (with 1 x 1 binning); objects on the order of 76 centimeters (30 inches) across are resolved.] North is up.
</p>
The University of Arizona, Tucson, operates HiRISE, which was built by Ball Aerospace &amp; Technologies Corp., Boulder, Colo. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project for NASA's Science Mission Directorate, Washington.
NASA/JPL-Caltech/Univ. of Arizona
<b><a rel="nofollow" class="external text" href="https://photojournal.jpl.nasa.gov/catalog/PIA21458">Catalog page</a></b><span style="white-space:nowrap"> <b>·</b></span> Full-res (<a rel="nofollow" class="external text" href="https://photojournal.jpl.nasa.gov/jpeg/PIA21458.jpg">JPEG</a><span style="white-space:nowrap"> <b>·</b></span> <a rel="nofollow" class="external text" href="https://photojournal.jpl.nasa.gov/tiff/PIA21458.tif">TIFF</a>)