Sulfates on Mars: Indicators of Aqueous ProcessesRecent analyses by MER instruments at Meridiani Planum and Gusev crater and the OMEGA instrument on Mars Express have provided detailed information about the presence of sulfates on Mars [1,2,3]. We are evaluating these recent data in an integrated multi-disciplinary study of visible-near-infrared, mid-IR and Mossbauer spectra of several sulfate minerals and sulfate-rich analog sites. Our analyses suggest that hydrated iron sulfates may account for features observed in Mossbauer and mid-IR spectra of Martian soils [4]. The sulfate minerals kieserite, gypsum and other hydrated sulfates have been identified in OMEGA spectra in the layered terrains in Valles Marineris and Terra Meridiani [2]. These recent discoveries emphasize the importance of studying sulfate minerals as tracers of aqueous processes. The sulfate-rich rock outcrops observed in Meridiani Planum may have formed in an acidic environment similar to acid rock drainage environments on Earth [5]. Because microorganisms typically are involved in the oxidation of sulfides to sulfates in terrestrial sites, sulfate-rich rock outcrops on Mars may be a good location to search for evidence of past life on that planet. Whether or not life evolved on Mars, following the trail of sulfate minerals will lead to a better understanding of aqueous processes and chemical weathering.
Document ID
20060051799
Acquisition Source
Ames Research Center
Document Type
Conference Paper
Authors
Bishop, Janice L. (NASA Ames Research Center Moffett Field, CA, United States)
Lane, Melissa D. (Planetary Science Inst. Tucson, AZ, United States)
Dyar, M. Darby (Mount Holyoke Coll. South Hadley, MA, United States)
Brown, Adrian J. (NASA Ames Research Center Moffett Field, CA, United States)