NASA Mars Picture of the Day: Defrosting Richardson Dunes

Mars Global Surveyor Mars Orbiter Camera

MGS MOC Release No. MOC2-492, 23 September 2003

NASA/JPL/Malin Space Science Systems

This is a mid-southern spring view, taken in August 2003,
of defrosting patterns on sand dunes in Richardson Crater.
The picture was acquired by the
Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC). The
frost on these dunes might be a combination of frozen
carbon dioxide left over from the previous winter, and
water ice. As the ices sublime away, they create dark spots.
Winds create dark streaks, either by moving the dark sand
that underlies the frost, or by removing frost to expose
the sand. Alternatively, the frost itself is roughened by
the wind or has been made coarse by wind and sublimation
processes. The Richardson dune field undergoes a long series
of changes as it defrosts from late winter through
spring and into early summer. Summer will arrive at the
end of September 2003. This picture is located
near 72°S, 181°W, and covers an area 3 km (1.9 mi)
across. Sunlight illuminates the scene from the upper 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.