XI. Planets and life around other stars (original) (raw)
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Abstract
This chapter discusses various factors that influence the probability of life in planets of the solar system and other stars. An essential prerequisite to life is the availability of a chemical system that can store, read, and write very complex genetic information. Such a high level of complexity requires a chemistry within which stable molecules of intricate structure and high information content can be synthesized, read, and transcribed. The chemical flexibility that is essential to synthesizing and reading information-bearing molecules requires that these processes occur in a liquid. An appropriate solvent for the large information-bearing molecule is also required. Many elements can form chains of atoms that are poorly suited to information storage and retrieval either in solution or in the pure state. Based on these and various other considerations, life would be based on the chemistry of carbon, especially polar carbon compounds. Carbon's ability to produce complex, diverse, and stable long-chain compounds that dissolve in water and in a variety of other polar solvents makes it very attractive. The necessity for mobilizing polar carbon compounds to permit the solution of a wide variety of biochemicals requires a solvent. The most abundant solvent in the universe is water, a compound of the first and third most abundant elements in the cosmos. The second most abundant polar molecule in the universe after water is ammonia.
Publication:
International Geophysics Series
Pub Date:
2004
DOI:
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