EVIDENCE IN METEORITES OF FORMER LIFE: THE ORGANIC 



COMPOUNDS IN CARBONACEOUS CHONDRITES ARE 



SIMILAR TO THOSE FOUND IN MARINE SEDIMENTS 



W. G. Meinschein 

 Esso Research and Engineeriufi Co., Linden, X.J. 



Bartholomew Nagy, Douglas J. Hennessy 



Fordham I'nhersity, New York, N.Y. 



Recently, the composition of the hydrocarbons in the Orgueil carbonaceous 

 chondrite has been proposed as evidence for biological activity in the parent 

 body.' This apparently novel use of hydrocarbons has created great interest 

 and is the subject of appreciable controversy. 



The proposal that certain meteorites were once a part of an extraterrestrial 

 biosphere is not new. Analyses of carbonaceous substances in chondrites 

 were published first more than 120 years ago. Berzelius,"' in 1834, speculated 

 about and decided against the possibility that the humic acid type substances 

 in the Alais meteorite were biological products. Wohler,'*-^ however, thought 

 that the ozocerite type constituents in the Kaba chondrite, which he investi- 

 gated, in 1858, were "undoubtedly of organic origin;" but Berthelot did not 

 share Wohler's belief that a resemblance to terrestrial organic matter was 

 proof of a biological origin. Berthelot'''' hypothesized a reaction of metallic 

 carbides and water to explain the presence of "petroleum-like" hydrocarbons 

 in the Orgueil stone. Although Mueller'^ noted experimental evidence against 

 the carbide theory of Berthelot, the "chlorobitumens" which were reportedly 

 isolated from the Cold Bokkevelt by Mueller^ were not suggested as organic 

 products. All of these observational and elemental analyses were far less 

 definitive than the analyses that have been made possible by modern technicjues 

 and instruments and recent accjuisition of paleobiological reference data. 

 Investigations of terrestrial biotic matter and modern analytical methods, 

 now, provide a basis for speculations about extraterrestrial life. 



Spectrometric, chromatographic, and new microscopic methods were not 

 utilized in the study of the carbonaceous substances in meteorites before 1954. 

 Boato"* nieasured the abundances of stable carbon and hydrogen isotopes in 

 14 meteorites. He noted that "the carbonaceous material is, of course, not 

 derived from living sources, but it is noteworthy that the range of variation 

 in C'-^ in the meteorites is of the order of the depletion observed in a terrestrial 

 process involving loss of volatile compounds."^ Recent investigations, how- 

 ever, do not support the view that a loss of volatile compounds leads to a 

 depletion of C''* in sedimental organic matter. Silverman and Epstein'^ and 

 Park and Epstein" have found that ecology exerts the principal control on 

 terrestrial, organic C'-^ contents. Lipids, which are the major volatile con- 

 stituents of plants and animals, have lower C'^ contents than other organic 

 compounds." 



Boato's deuterium determinations provided evidence of the extraterrestrial 

 origin of meteorites. He found much greater concentrations of deuterium in 

 the combined water which were removed from the Orgueil stone at temperatures 



553 



