spacetoday.net: Mars subsurface ice is patchy

Posted: Thu, May 3, 2007, 7:32 AM ET (1132 GMT)
Phoenix Mars lander illustration (Univ. of Arizona)

The depths below the surface where water ice exists near the polar regions of Mars depends strongly on the properties of the surface, scientists reported this week. In a paper published in Thursday's issue of the journal Nature, scientists analyzed infrared images of the polar regions of the planet taken by NASA's Mars Odyssey spacecraft to measure the changes in temperature of the surface, a measure of how close to the surface the thermally-stable layer of water ice lies. Researchers found that the ice was much closer to the surface in dusty regions, while much farther below the surface in rocky areas the "pump" heat into subsurface layers. The results means that NASA's Phoenix spacecraft, scheduled for launch later this year to land in the planet's far-northern regions, might find differences in the depth of the water ice layer in spots as little as a meter apart.