Radar Shows Water Ice Layered on Mars

"The radar sees through icy layers to the lower boundary,
which in places is as deep as 2.29 miles (3.7 kilometers) below the surface.
The strength of the lower echo suggests that the intervening material
is nearly pure water ice." - European Space Agency


Upper B&W radargram data, by ESA's Mars Advanced Radar for Subsurface
and Ionospheric Sounding (MARSIS), shows subsurface of water-ice-rich layered deposits
that surround the Martian south pole. White line in lower color topography shows path on
ground over which Mars Express orbiter flew. The radar and topographic images are 777 miles
(1,250 kilometers) wide. Credits: NASA/JPL/ASI/ESA/Univ. of Rome/MOLA Science Team.

European Space Agency reports: "The amount of water trapped in frozen layers over Mars' south polar region is equivalent to a liquid layer about 36 feet (11 meters) deep covering the planet. This new estimate comes from mapping the thickness of the dusty ice by the ESA Mars Express radar instrument that has made more than 300 virtual slices through layered deposits covering the pole. The radar sees through icy layers to the lower boundary, which in places is as deep as 2.29 miles (3.7 kilometers) below the surface. The strength of the lower echo suggests that the intervening material is nearly pure water ice. Near the image center, the bright lower echo abruptly disappears for unknown reasons. The time delay between the two echoes reaches a maximum of 42 microseconds left of center, corresponding to a thickness of 2.17 miles (3.5 kilometers) of ice. The total elevation difference shown in the topographic map is about 2.48 miles (4 kilometers) between the lowest surface (purple) and the highest (red). For more, see ESA.