Irradiation of Icy Cometary Analogs: Its Relevance in Reference to Chemical Evolution and the Origin of Life

Abstract

The study of comets has, with good reason, intensified over the past few years. Comets are minor bodies in our solar system which are almost as old as the solar system itself. They provide unique information about chemical evolution processes that occurred at early stages of the solar system. Besides that, they are dynamically connected with other small objects all over the solar system (Weissman and Levison, 1996). In addition, within the scenario of the origin of life, Chamberlin and Chamberlin (1908) were the first to suggest that extraterrestrial material could have played an important role in terms of having contributed to the organic matter on the Earth, influencing abiotic synthesis and biological evolution. Later, J. Oró (1961) reworked this hypothesis, implying a specific role for comets as raw material providers for chemical evolution on Earth, and, since then, this line of research has been widely investigated, thus reinforcing this idea (Hartman et al., 1985; Negrón-Mendoza et al., 1994; Oró and Lazcano, 1997; Oró and Cosmovici, 1997; Irvine, 1998, Colín-García et al, 2008 in press). This means that, not only local processes, such as UV irradiation and electrical discharges on the primitive atmosphere, were important in triggering necessary reactions on the early Earth, but extraterrestrial contributions were also of great significance.