Editor's Summary

3 May 2007

Digging for ice on Mars

Theoretical models predict that the depth at which water ice is stable in the subsurface of Mars will vary due to local surface features such as rocks and slopes, and the thermal inertia of the ground above the water. So far, measurements have been limited to overviews of the several-hundred-kilometre footprint covered by the -ray spectrometer on-board the Mars Odyssey spacecraft. But Joshua Bandfield has now used the seasonal temperature response of the martian surface (from Odyssey's THEMIS package) to map water ice distribution at the sub-kilometre scale. The observations reveal significant regional and local water-ice depth variability at potential landing sites for the Mars Phoenix mission due for launch later this year. The Phoenix lander's robotic arm will be able to dig up to half a metre or so into the soil to search for water ice, and these results suggest that it may encounter considerable variation in the depth to the ice layer.

Letter: High-resolution subsurface water-ice distributions on Mars

Joshua L. Bandfield

doi:10.1038/nature05781

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