NASA Mars Picture of the Day: June 2004 Autumn Dunes

Mars Global Surveyor
Mars Orbiter Camera

MGS MOC Release No. MOC2-750, 7 June 2004

NASA/JPL/Malin Space Science Systems

Presently, it is autumn in the southern hemisphere of Mars.
Sand dunes at high and middle latitudes are becoming cold and
frosted. This frost, probably water ice, is persistent
enough that it is still present around 2 p.m. in the
afternoon, when Mars Global Surveyor (MGS) flies over these
dune fields. This MGS Mars Orbiter Camera (MOC)
image shows an intracrater dune field at
59.4°S, 158.9°W, as it appeared last week
on 3 June 2004. In summer, these dunes would be very dark
relative to the substrate on which they occur. In autumn,
as shown here, they begin to accumulate frost that will
last through the coming winter. Southern hemisphere winter
will arrive around 20 September 2004.
The image covers an area about 3 km (1.9 mi) across and is
illuminated by sunlight 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.