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Project Progress

We are examining the availability of resources that might support life on Mars, as a way of understanding both the potential for life there and the nature of planetary habitability. The general requirements to support life include availability of liquid water, access to the biogenic elements, and a source of energy to drive metabolism. We are exploring each of these in the Martian environment, their availability and accessibility, and potentially observable indicators of the extent to which they have acted. Progress during the past year is in three areas:

• Availability of liquid water on Mars: We are examining conditions under which liquid water can exist in the Martian polar regions and possibly be capable of supporting life. Thin films of water can exist and be stable even at sub-zero (^oC) temperatures that can occur at moderate and high axial obliquity (tilt of polar axis). (Work with Mellon, Varnes, and Ley.)
• Availability of geochemical energy on Mars: We are estimating the amounts of energy available through chemical weathering of minerals in Martian systems that might be able to support organisms, in analogy with organisms that live in similar environments on Earth. Using compositional information derived from spacecraft and from the Martian meteorites, we calculate that there should be substantial quantities of energy available in Martian hydrothermal systems. (Work with Varnes and McCollom.)
• Mineralogy of Martian hydrothermal systems: NAI post-doc Sara Martinez-Alonso is using Mars Global Surveyor Thermal Emission Spectrometer data to search for minerals indicative of hydrothermal alteration. As such systems are potential environments both for an origin and for the long-term existence of life, they are of special interest. Work to date has involved development of data analysis tools and algorithms.