隕石母天体における有機物進化をひも解く

抄録

Insoluble organic matter (IOM) in meteorites shows large variations in molecular structures. At least some of the variations attribute to the differences of parent asteroidal processes including aqueous alteration and thermal metamorphism. In general, alteration/metamorphism reduces the hydrogen, nitrogen and oxygen contents of the organic matter through decompositions of the aliphatic and oxygen-containing moieties. However, alteration effects are not only destructive but can also be constructive. For example, macromolecular organic residues can be condensed from simple molecules such as formaldehyde and ammonia with the presence of liquid water. This review covers the results from recent works on analyses and experimental studies of organic matter (mostly IOM) in meteorites, and discusses the chemistry plausibly occurred at the early stage of planetesimal formations.