Mineralogy Considerations for 2003 MER Site Selection and the Importance for Astrobiology

Much of the discussion of site selection on Mars is based on interesting images of the surface combined with safety issues. I argue that the two rovers should be sent to mineralogically distinct regions. Compositional information is still poorly constrained on Mars; however, the instruments on the 2003 Mars Exploration Rovers (MERs) will provide a unique opportunity for detailed characterization including mineral identification. There is strong motivation for sending one rover to a "typical" region on Mars to be used as a ground truth for the Thermal Emission Spectrometer (TES), while the other rover should be sent to a site where water and chemical alteration are likely to have occurred. Determining the mineralogy of the Martian surface material provides information about the past and present environments on Mars which are an integral aspect of whether or not Mars was suitable for the origin of life. Understanding the mineralogy of terrestrial samples from potentially Mars-like environments is essential to this effort.