PIA12289: The Changing Dunes of Wirtz Crater
 Target Name:  Mars
 Is a satellite of:  Sol (our sun)
 Mission:  Mars Reconnaissance Orbiter (MRO)
 Spacecraft:  Mars Reconnaissance Orbiter (MRO)
 Instrument:  HiRISE
 Product Size:  4500 x 3000 pixels (w x h)
 Produced By:  University of Arizona/HiRISE-LPL
 Other  
Information: 
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 Full-Res TIFF:  PIA12289.tif (40.52 MB)
 Full-Res JPEG:  PIA12289.jpg (2.437 MB)

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The large dark feature is a classic Martian sand dune. Most sand on Earth is made from the mineral quartz, which is white and bright. On Mars, most sand is composed of dark basalt, a volcanic rock. For this reason, dunes on Mars are darker than those on Earth.

The dunes in this observation, within Wirtz Crater, are known as "barchans." The steepest slope is on the eastern (right) side, partially in shadow, and represents the direction the dune is migrating as the sand is blown and transported by the wind. Small ripples are visible on much of the dune surface. The dark streaks on the dune are tracks left by passing vortices known to us as dust devils. These raise dust off the dune, revealing a darker substrate.

This is a stereo pair with ESP_021893_1315.

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

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

Image Addition Date:
2017-01-19