Isotopic compositions of nitrogen and noble gases in mar-tian meteorites not only help in their identification, but provide useful insights into their origin and evolution and that of the Red Planet While Mars appears pretty much a planet like ours, it has an atmosphere much different in isotopic signatures of nitrogen, argon and xenon, and a mantle that has much less radiogenic noble gas isotopic signatures. These reflect differences in planetary evolution in these two planets. At the same time, similarity in nitrogen isotopic composition of mantles and relative concentrations of noble gases in their atmospheres may indicate some similarity in the nature of precursors and planetary evolution While conventionally CI carbonaceous chondrites are proposed as a universal precursor of terrestrial planets, the isotopic compositions of nitrogen and oxygen suggest Mars to have formed by the accretion (in a ratio of 74:26) of enstatite and ordinary chondrite-like materials.
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