PIA22456: Barchan Pac-Man
 Target Name:  Mars
 Is a satellite of:  Sol (our sun)
 Mission:  Mars Reconnaissance Orbiter (MRO)
 Spacecraft:  Mars Reconnaissance Orbiter (MRO)
 Instrument:  HiRISE
 Product Size:  2880 x 1800 pixels (w x h)
 Produced By:  University of Arizona/HiRISE-LPL
 Other  
Information: 
Other products from ESP_054515_1930
 Full-Res TIFF:  PIA22456.tif (5.191 MB)
 Full-Res JPEG:  PIA22456.jpg (1.039 MB)

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The map is projected here at a scale of 50 centimeters (19.7 inches) per pixel.
[The original image scale is 55.9 centimeters (22.0 inches) per pixel (with 2 x 2 binning); objects on the order of 168 centimeters (66.1 inches) across are resolved.] North is up.

This image from NASA's Mars Reconnaissance Orbiter shows barchan sand dunes, common on Mars and often forming vast dune fields within very large (tens to hundreds of kilometers) impact basins. The regions upwind of barchans are usually devoid of sandy bedforms, so if you were walking in a downwind direction, then the barchans would seem to appear out of nowhere.

As you walk downwind, you would notice the barchans link up ("joining arms") and eventually slope into featureless sand sheets. We call this progression of dunes a "Herschel-type dune field" named after the first place this sequence was described: Herschel Crater.

But here is something interesting: a barchan dune filling the upwind portion of a small impact crater in a Pac-Man-like shape. This "dune-in-a-crater" is nearly at the highest extent of the field. It is also probably a rare configuration, and over the next few tens of thousands of years the sand will be blown out of the crater.

The University of Arizona, Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., Boulder, Colorado. 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.

Image Credit:
NASA/JPL-Caltech/Univ. of Arizona

Image Addition Date:
2018-05-14