Ferrate(VI) as a possible oxidant on the Martian surface.
Viking 'Biological' experiments (Oyama et al. 1976, Levin & Straat 1977) revealed an unexpected chemical activity in the surfam material, which in some ways resembled biology but was ultimately explained by a rather complex chemistry. It was shown, in these experiments that moisturizing Martian soil resulted in oxygen evolution, while addition of a bacterial nutrient solution (14G formate, glycine, lactate, etc.) released 14C02, dong with some oxygen. These observations indicated the presence of a strong oxidant on Martian surface, or, most probably, several different oxidants (Klein 1978). The nature of the oxidants in Mars soil, and their distribution, are important for choosing Martian landing sites. Iron as an one of the most abundant elements in Martian soil, deserves attention in this context, since it has a whole set of oxidation states, from 0 to +6, even though in terrestrial conditions only Fe(O), Fe(+2) and Fe(+3) are commonly found. Fe(+4, +5) are unstable, but Fe(+6) has been characterized in some detail. Though it was never identified as a natural compound on the Earth, it is stable enough under some conditions (highly alkaline solutions, lack of reductants, dry atmosphere, low temperature) that are not normally encountered in the terrestrial environment, but still can be considered as a possibility in Martian soil. Here are discussed ferrate(VI) formation and accumulation in Martian soil, and experimental data are presented on the spectral characterization and chemical behavior under conditions simulating the Viking 'biological experiments'.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC); USDOE Laboratory Directed Research and Development (LDRD) Program; National Aeronautics and Space Administration (NASA)
- DOE Contract Number:
- DE-AC02-06CH11357
- OSTI ID:
- 924998
- Report Number(s):
- ANL/ER/CP-103802; TRN: US200807%%133
- Resource Relation:
- Conference: Bioastronomy '99: A New Era in Bioastronomy; Aug 2-6, 1999; Kohala Coast, Hawaii
- Country of Publication:
- United States
- Language:
- ENGLISH
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