Abstract Different estimates based on dynamical considerations, lunar cratering rates, Solar System chemical abundances, and the single-impact theory on the origin of the Earth-Moon system suggest that comets and other related small, volatile-rich primitive minor bodies captured by the Earth during the early Archean must have been a major source of volatiles on our planet. It is likely that a substantial fraction of the organic molecules present in the colliding cometary nuclei, which may have included nitrogen bases and the precursors of amino acids, were destroyed due to the high temperatures and shock wave energy associated with the collision. However, the presence of H2O, CN, CH, CO, CO2 and other carbon-bearing molecules and radicals in the atmosphere of the Sun and in circumstellar shells around carbon-rich stars suggests that at least simple carbon species could have survived the cometary collisions. Under the anoxic conditions thought to prevail in the prebiotic terrestrial paleoatmosphere, the post-collisional formation of a large number of excited molecules and radicals, and the rapid quenching of the expanding gaseous ball may have led, upon rapid cooling, to the formation of molecules of biogenic elements and to their eventual deposition in localized environments where complex organic compounds of biochemical significance may have been produced and accumulated.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    The cometary contribution to prebiotic chemistry


    Contributors:
    Oro, J. (author) / Mills, T. (author) / Lazcano, A. (author)

    Published in:

    Publication date :

    1991-01-01


    Size :

    9 pages




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English



    The cometary contribution to prebiotic chemistry

    Oro, J. / Mills, T. / Lazcano, A. | NTRS | 1992


    The cometary connection with prebiotic chemistry

    Delsemme, A. H. | Online Contents | 1984


    Sulfur chemistry in cometary comae

    Rodgers, S.D. | Online Contents | 2006


    Sulfur chemistry in cometary comae

    Rodgers, S.D. / Charnley, S.B. | Elsevier | 2005


    Sulfur chemistry in cometary comae

    Rodgers, S. D. / Charnley, S. B. / COSPAR | British Library Conference Proceedings | 2006