The chemical and morphological structures of comets and interstellar dust are reviewed to demonstrate the feasibility of comets providing the necessary prebiotic molecules for the formation of life on the early earth. The chemical evolution of interstellar dust is shown to be the source of organics in comets, and the molecules observed in the grains are listed as are the products resulting from grain photolysis. It is emphasized that comets could only transfer prebiotic molecules to the earth if they are fluffy aggregates that break up into fine fragments. The contributions to the early earth are considered in terms of the competition between the evolution of the living organisms and the destructive effects of impacts. It is considered that life began as the bombardment during the first 5 x 10 exp 8 years began to tail off.
The seeding of life by comets
Advances in Space Research ; 12 , 4 19
1992-01-01
Sonstige
Keine Angabe
Englisch
Elsevier | 1991
|Elsevier | 1987
|NTRS | 1987
|Comets and life in the Universe
NTRS | 1995
|Comets and Life in the Universe
Online Contents | 1994
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