Diamond formation in interstellar clouds and meteoritic parent bodies

Abstract

It is shown based on laboratory experiments that diamond could havenucleated as a result of UV photolysis of interstellar ice in molecular clouds, and grown with further UV irradiation in diffuse clouds. The present study supports the occurrence of diamonds in molecular clouds, and suggests that diamonds are ubiquitous in space. The various characteristics of nano-diamonds in meteorites can be explained well using this new formation route. Furthermore, we also found that diamonds could be formed by the aqueous alteration and the subsequent thermal metamorphism of interstellar organic materials in the parent bodies of carbonaceous chondrites.