NASA Mars Reconnaissance Orbiter HiRISE images February 22, 2012

– Well-Speckled Polar Dunes http://hirise.lpl.arizona.edu/ESP_025579_2580

In this image, taken during the northern spring season, the dunes and ground are still covered in seasonal frost.

– Utopia Planitia Scallops, Polygons, and Boulders http://hirise.lpl.arizona.edu/ESP_025620_2275

This terrain is covered by pits and scallops (pits open on one side), perhaps due to collapse after sublimation of subsurface ice.

– Dunes in Late Fall: Frost in the Ripples http://hirise.lpl.arizona.edu/ESP_025679_1300

These dunes in Aonia Terra are being monitored for changes such as gullies, which form over the winter from the action of carbon dioxide frost.

– Imaging in Deep Shadows http://hirise.lpl.arizona.edu/ESP_025680_1350

This image of an impact crater was acquired when the sun was just 11 degrees above the horizon, so a long shadow extends over most of the crater interior.

All of the HiRISE images are archived here: http://hirise.lpl.arizona.edu/

Information about the Mars Reconnaissance Orbiter is online at http://www.nasa.gov/mro. The mission is managed by NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology, for the NASA Science Mission Directorate, Washington, D.C. Lockheed Martin Space Systems, of Denver, is the prime contractor and built the spacecraft. HiRISE is operated by the University of Arizona. Ball Aerospace and Technologies Corp., of Boulder, Colo., built the HiRISE instrument.