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Project Progress

The Phoenix Mars Lander touched down on May 25, 2008 at a latitude of 68 degree North, where the Mars Odyssey Gamma Ray Spectrometer Instrument Suite observed shallow ground ice and equilibrium models predicted the presence of ice beneath a layer of dry soil. Indeed, the Lander has observed volatile material below a loose layer of soil.

Several studies are being devoted to this mission. Climate models simulate the exchange of water vapor between the atmosphere and the subsurface ice to reconstruct the history of the ice. One of the results of this study is that the ice nearest to the surface is likely only on the order of 50 thousand years old. Preliminary results are published in the Lunar and Planetary Science Conference Proceedings, abstract #1479 (2008).

Another component of this investigation involves theoretical studies in conjunction with laboratory experiments at the Caltech Ice Lab, where, for the first time, vapor deposited ice has been produced at Mars pressure conditions. This form of ice is expected where Phoenix landed. The lab experiments lead to the conclusion that interstitial soil spaces can be almost completely filled with ice. Additional results of this study can be found in T.L. Hudson, O. Aharonson, and N. Schorghofer. Laboratory experiments and models of diffusive emplacement of ground ice on Mars. Submitted to Journal of Geophysical Research (2008).