NASA Mars Picture of the Day: Summer South Polar Cap 04-13-2004

Mars Global Surveyor Mars Orbiter Camera

MGS MOC Release No. MOC2-695, 13 April 2004

NASA/JPL/Malin Space Science Systems

The martian south polar residual ice cap is composed
mainly of frozen carbon dioxide. Each summer, a little
bit of this carbon dioxide sublimes away. Pits grow
larger, and mesas get smaller, as this process continues
from year to year.
This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC)
image shows a view of a small portion of the south polar
cap as it appeared in mid-summer in January 2004. The dark
areas may be places where the frozen carbon dioxide contains
impurities, such as dust, or places where sublimation of
ice has roughened the surface so that it appears darker because
of small shadows cast by irregularities in the roughened surface.
The image is located
near 86.9°S, 7.6°W.
The image covers an area about 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.