Happy St. Valentine's Day from the Red Planet! The Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) captured this unique view of a bright, heart-shaped mesa in the south polar region on November 26, 1999. This feature is located in the Promethei Rupes region near 79.6°S, 298.3°W. Sunlight illuminates the scene from the lower left. The heart is about 255 meters (279 yards) across. The presence of this mesa indicates that the darker, rough terrain that surrounds it was once covered by a layer of the bright material.
Note added 1:45 p.m. PST, 11 February 2000:
If the heart looks
to you like it is a pit (negative relief) rather than a mesa (positive relief),
that is because there are two effects that make this a challenging object to
see. Sunlight illuminates the heart from the lower left, thus the lower left
wall of the heart looks bright because it is reflecting this sunlight. The
problem here is frost. Some very small amounts of residual frost are seen on the
slopes facing away from the sunlight (toward the lower right and toward the
top). MOC images in the martian polar regions can sometimes fool the eye because
a frosted slope might at first glance seem to be a sunlit slope. This picture
was taken in late southern spring in a region that spends each winter and most
of each spring completely buried in bright frost.
