THE METEORITIC INPUT ON MARS - INFLUENCE ON ORGANIC GEOCHEMISTRY

摘要

Pristine, cosmic material, which is continuously delivered to the Martian surface through meteoritic dust infall, contains considerable quantities of organic matter - the prerequisites for the evolution of life. Organic material has, however, not yet been detected on the surface of the planet. The lack of organic material on the Martian surface despite of the continuous meteoritic delivery is ascribed to the reactivity of the Martian soil and to the processes related to entry and impact of meteoritic matter. We present a study of regolith mixing relationships, in particular stressing the meteoritic contribution in the Martian soil. According to the inferred meteoritic contribution, about 0.8 to 0.5 wt% C is missing in the Martian soils at the top level and should be present in deep soils, respectively. Based on the organic carbon content of carbonaceous chondrites, vertical soil profiles can be simulated.