Annotated Version
This map shows the topography of the south polar region of Mars, including
topography buried by thick deposits of icy material. The map is a
combination of surface elevation data acquired by the Mars Orbiter Laser
Altimeter aboard NASA's Mars Global Surveyor orbiter, and subsurface
elevation data acquired by the Mars Advanced Radar for Subsurface and
Ionospheric Sounding (MARSIS) aboard the European Space Agency's Mars
Express orbiter.
The black line shows the boundary of the south polar layered deposits, an
ice-rich geologic unit that was probed by MARSIS. Elevation values within
the black outline, as measured by MARSIS, show the topography at the
boundary between the layered deposits and the underlying material, an
interface known as the "bed" of the deposits. The elevation of the terrain
is shown by colors, with purple and blue representing the lowest areas,
and orange and red the highest. The total range of elevation shown is
about 5 kilometers (3 miles). The radar data reveal previously undetected
features of topography of the bed, including depressions as deep as 1
kilometer (0.6 miles) shown in purple in the near-polar region. The
boundary of the layered deposits was mapped by scientists from the U.S.
Geological Survey. The dark circle in the upper center is the area
poleward of 87 degrees south latitude, where MARSIS data cannot be
collected. The map covers an area 1,670 by 1,800 kilometers (1,035 by
1,115 miles).
MARSIS is an instrument on the European Space Agency's Mars Express
orbiter. NASA and the Italian Space Agency jointly funded the instrument.
The Mars Orbiter Laser Altimeter flew on NASA's Mars Global Surveyor
orbiter.
