Organic compounds in meteorites and their origins

Abstract

CI and C2 carbonaceous chondrites contain several percent of organic matter, mainly as a bridged aromatic polymer containing COOH, OH, and CO groups, as well as heterocyclic rings containing N, O, and S. The remaining 5-30% includes the following compound classes, either present initially or generated by solvolysis: alkanes (mainly normal), alkenes, arenes alicyclics, alcohols, aliphatic, carboxylic acids, purines, pyrimidines, and other basic N-compounds, amino acids, porphyrin-like pigments, carbynes, etc. On the basis of laboratory esperiments, it appears that these compounds formed in the solar nebula, by catalytic Fischer-Tropsch) reactions of CO, H2, and NH3 at 360-400K, 10-5 atm. The onset of these reactions was triggered by the formation of suitable catalysts (magnetite, hydrated silicates) at these temperatures. Such reactions may be a source of prebiotic carbon compounds on the inner planets, and interstellar molecules.