Mars Picture of the Day: Defrosting Sand Dunes

Mars Global Surveyor Mars Orbiter Camera

MGS MOC Release No. MOC2-399, 22 June 2003

NASA/JPL/Malin Space Science Systems

When spring comes to the southern hemisphere of
Mars, dark spots begin to form on sand dunes
covered with carbon dioxide frost. This
Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC)
image shows a dune field near
61.8°S, 160.5°W in early spring.
The processes that form the dark spots
remain mysterious. The spots might form
at the locations of the thinnest frost,
the coarsest sand grains, or at interfaces
between two different types of material
surfaces (e.g., between dune and surrounding
plain). The area shown
here is illuminated from the
upper left and covers an area 3 km (1.9 mi)
wide.

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.