In the winter, these dunes in an unnamed crater east of Proctor Crater are covered with seasonal carbon dioxide frost (dry ice). In the spring, the frost gradually evaporates but lingers in protected regions. In this color image bright ice deposits in sheltered areas highlight the ripples on the dunes.

These dunes were imaged during the first year of MRO’s mission. Images taken now in the second Martian spring can be compared to the previous year to study interannual variability.


Written by: Candy Hansen

All of the images produced by HiRISE and accessible on this site are within the public domain: there are no restrictions on their usage by anyone in the public, including news or science organizations. We do ask for a credit line where possible: Image: NASA/JPL/University of Arizona

For information about NASA and agency programs on the Web, visit: http://www.nasa.gov. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif., manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems is the prime contractor for the project and built the spacecraft. The HiRISE camera was built by Ball Aerospace and Technology Corporation and is operated by the University of Arizona. The image data were processed using the U.S. Geological Survey’s ISIS3 software.