7.2 - Cosmochemical Evolution

Xenology: An Introduction to the Scientific Study of Extraterrestrial Life, Intelligence, and Civilization

First Edition

Robert A. Freitas Jr., Xenology: An Introduction to the Scientific Study of Extraterrestrial Life, Intelligence, and Civilization, First Edition, Xenology Research Institute, Sacramento, CA, 1979; http://www.xenology.info/Xeno.htm

Great clouds of organic molecules have been discovered drifting between the stars, presumably formed by various natural processes.^{1002,2219,2220,2221} Radioastronomers have seen relatively complex compounds hiding deep in inter stellar space, including methyl alcohol, ethyl alcohol, cyanogen, formaldehyde, formic acid and ether,^1002,2217 and the search is on for amino acids.

Compounds of carbon and hydrogen, particularly cyanogen, methane and hydrocarbon radicals, are detected on the surfaces of stars.^1973,2297 To find the limits of such processes, Dr. John Oró performed an experiment which simulated a hot stellar plasma. Using a graphite resistance apparatus and a plasma torch device temperatures from 1500-4000°C were obtained. Methane, ammonia and water were introduced continuously. The products were condensed at room temperature and allowed to interact for a few hours before analysis. Three amino acids appeared -- alanine, glycine, and aspartic acid -- along with hydrogen cyanide and a host of other organics.¹⁰⁷²

There is no doubt that the carbon compounds essential for the development of Earthly life are ubiquitous. Organics have been detected on the Moon,²⁴⁴³ other planets,^2037,2046 asteroids,²⁰³⁷ and in comets.^1973,2222

The Murcheson rock which fell in Australia on September 28, 1969 contains 2 × 10^-7 moles of amino acids per gram of meteorite, which is more than many desert sands on Earth.⁵²¹ These amino acids correspond rather closely to those produced in prebiotic synthesis experiments performed in the laboratory.²²⁵

The Orgueil meteorite contains approximately 7% organic matter, including hydrocarbons, fatty acids, aromatics, porphyrins, nucleic acid bases, optically active lipids, and a variety of polymeric material.¹⁰⁷⁵ On the basis of the amounts of carbon compounds detected in various meteorites, researchers have concluded that these interplanetary wanderers could have brought as much as 5 × 10¹⁰ kg of formaldehyde and 3 × 10¹¹ kg of amino acids to Earth during the first eon of its existence.¹³⁴

Taken together, these studies of meteorites, comets, planets and interstellar matter strongly suggest that chemical evolution is a continuing and commonplace occurrence in all parts of the cosmos. The basic constituents necessary for the emergence of life are universal. This implies that life should be widely distributed throughout the Galaxy, wherever conditions are clement, since the required ingredients of abiogenic processes are abundantly available everywhere.