Annotated Version
This map shows the topography of the south polar region of Mars. The data
were collected by the Mars Orbiter Laser Altimeter aboard NASA's Mars
Global Surveyor orbiter between 1997 and 2001. 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 black line shows the boundary of the
south polar layered deposits, an ice-rich geologic unit that was probed by
the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS)
aboard the European Space Agency's Mars Express orbiter.
The radar data indicate that the deposit is more than 3.7 kilometers
(2.3 miles) thick in places, and that the material consists of nearly pure
water ice, with only a small component of dust. The MARSIS team also
determined that the total volume of ice in the layered deposits is
equivalent to a water layer 11 meters (36 feet) deep, if spread evenly
across the planet. 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 image 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.