Comets and life in the Universe.

The notion that comets supplied the primitive Earth with the requisite chemical species for the process of chemical evolution, which is widely held to have led to the origin of life on Earth, has now gained considerable intellectual momentum since its first formulation in 1961. In fact, in the fall of 1991, the University of Wisconsin-Eau Claire hosted a well attended scientific meeting devoted solely to the discussion of this topic, entitled Comets and the Origin and Evolution of Life [see Special Issue of Origins of Life, P.J. Thomas (ed), vol. 21(5-6)]. As a result of the above meeting, the recently completed COSPAR/World Space Congress Symposium on Extraterrestrial Organic Chemistry and the Origins of Life, and numerous independent reports, the role of comets in the Earth's biogenesis has been thoroughly addressed in the literature. At this time, in light of a few recent findings, we present here a concise review of this topic together with a brief discussion of the possible role of cometary material in the origin of life elsewhere in the Universe.