Investigating the Surface Chemistry of Mars

摘要

One of the primary objectives of the Viking missions to Mars in the 1970s was to search for life. The landing crafts, or landers, detected extraordinary reactivity in the Martian soil, but no organic material. Numerous theories were put forth to explain the Viking data, most of which involved an oxidizing species in the Martian surface material. In December 1992, the Mars Oxidant Experiment (MOx) was selected as the U.S. contribution to the Russian Mars '96 mission. Two landers are scheduled for launch in November 1996 and should arrive at Mars in September 1997. This is the first mission in 20 years to conduct experiments on and near the surface of Mars. The MOx instrument, shown on the Russian lander in Figure 1, is designed to investigate the chemical nature of the Martian surface material, with particular emphasis on its oxidative character. The instrument uses fiber-optic technology to monitor real-time physicochemical changes in a suite of chemically sensitive thin-film materials, some in contact with the Martian surface, others exposed only to the atmosphere.