532 Annals New York Academy of Sciences 



imiits and primordial nobk- gases suggests a source material more primitive 

 than ordinary chondrites; yet the presence of high-temperature minerals 

 implies that this source material j)assed through at least one high-temperature 

 stage. These conditions would be satisfied by material expelled from the sun 

 in a gaseous state (Wood, 1958), and accreted to soUd bodies after condensation 

 and cooling (Urey, 1952). 



The exposure to liquid water could have occurred in subsurface regions of an 

 asteroid heated by extinct radioactivityor anotherinternal energy source. Sun- 

 light for photosynthesis would not reach these regions, but an appreciable 

 amount of free energy would be available from the conversion of olivine to 

 hydrated silicates. Although this source of energy is finite, it may have 

 served as the basis for the evolution of a nonphotosynthetic life form. 

 None of the isotopic data suggest the presence of life, however. The fractiona- 

 tion between sulfur and sulfate in Orgueil is in the opposite direction from that 

 observed for terrestrial sulfur bacteria. The carbon data are inconclusive, hav- 

 ing been determined on the total combustible carbon only, rather than on 

 individual compounds or fractions. The hydrocarbon data are also not con- 

 clusive, since the degree of resemblance to biogenic hydrocarbons and the ability 

 of nature to produce such a hydrocarbon distribution by purely abiotic (Miller- 

 Urey) reactions are still open to dispute. 



A cknowledgments 



I am greatly indebted to E. R. DuFresne, whose work provided many of the 

 basic data cited in this paper. I also want to express my gratitude to N. C. 

 Yang and Maria Tsong, who made available their unpublished data on the 

 organic matter in Orgueil, and to Frank W. Fitch, who contributed many valu- 

 able criticisms. 



References 



Unpulilishfd work. 



Proc. Lunar and Planetary Colloc|. 2(4): .SS. 

 .\nn. N.Y. Acad. Sci. 93('U): 649. 

 Rev. Mod. Phvs. 34: 287. 

 Science. 138: 4,1l. 

 Anders, K. & G. G. Golks. 1961. J. ('hem. I'-d. 38: .S<S. 

 BoATO, G. 1954. Geochim. et Cosniochim. .\cta. 6: 209. 

 Briggs, M. H. 1961. Nature. 191: 1137. 



Gai.vin, M. & S. K. Vaughn. 1960. Proc. l-'irsl Space Sciences Symposium. H. Kall- 

 mann iiiji, I'".d. North Holland Publishing Go. .Vmsterdam. 

 Cameron, A. G. VV. 19.S9. .\stroi)h_\ s. J. 129: 676. 

 Clayton, R. N. 1961. Private comnumication. 

 Clayton, R. N. 1962. lln|jul)lished work. 

 Craig, H. 1953. Geochim. el Cosmochim. .Acta. 3: .5,^ 

 Degens, E. T. & M. Bajor. 1962. To he ])ul.lished. 



Dul'RESNE, E. R. & E. .\noers. 1961. Geochim. el Cosmochim. Acta. 23: 200. 

 Dul'KESNE, v.. R. & E. .\nders. 1962(;. Geochim. el Cosmochim. .\cla. 26: 1085. 

 DuI'RESNE, E. R. & E. Anders. 1962Z). Geochim. el Cosmochim. .\cla. 26: 251. 

 Dul'^RESNE, E. R. & H. (i. TnoDE. 1961. Unpublished work. 

 Eberhardt, p. & .'\. Eberuardt. 1961. Z. Nalurforsch. 16A: 236. 

 Edwards, (j. & H. C. ITrey. 1955. (ieochim. el Cosmochim. .\cla. 7: 154. 

 EnMANN, W. D. & |. R. HiTiZENGA. 1959. Geochim. el Cosmochim. Acta. 17: 125. 

 Eisii, R. A., Ci. (;. Goi.ES & E. Anders. 1960. Aslrophxs. | 132: 243. 

 I'lTCH, F., H. P. ScHWARCz & E. Anders. 1962. Nature. 193: 1123. 

 Eredrtksson, K. 1962. Privale communication. 



