NASA Mars Picture of the Day: Nearly-defrosted Dunes

Mars Global Surveyor Mars Orbiter Camera

MGS MOC Release No. MOC2-948, 22 December 2004

NASA/JPL/Malin Space Science Systems

This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC)
image shows a group of north polar dunes in late spring,
just before the final patches of wintertime frost
sublimed away. The dunes beneath the frost are dark
because they contain minerals rich in reduced (unoxidized)
iron. The dune slip faces (the steepest
slopes on the dunes) point toward the upper right (northeast),
indicating that the dominant winds involved in sand
transport in this region blow from the lower left
(southwest). These dunes are located
near 76.3°N, 261.1°W. The image covers
an area about 3 km (1.9 mi) wide and
sunlight illuminates the scene from the lower left.

Malin Space Science Systems and the California Institute of Technology
built the MOC using spare hardware from the Mars Observer mission.
MSSS operates the camera from its facilities in San Diego, California.
The Jet Propulsion Laboratory’s Mars Surveyor Operations Project
operates the Mars Global Surveyor spacecraft with its industrial
partner, Lockheed Martin Astronautics, from facilities in Pasadena,
California and Denver, Colorado.