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5. Low-Temperature Condensates in Comets

Published online by Cambridge University Press:  12 April 2016

Abstract

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Recent observational data on the volatile fraction of comets are confronted with a model based on the fractional condensation, in the 80-100 °K range, of a higher-temperature equilibrium obtained from a solar mixture, more or less depleted in oxygen and in hydrogen. It is possible to almost duplicate the observational data, only by assuming that the solar ratio of C/0 is at least as large as 0.66 and that the hydrogen was drastically depleted by an unknown process in the primitive solar nebula. Although none of these two assumptions is at variance with present knowledge, the latter is sufficiently exotic to propose a simpler explanation, namely that comets could be made of interstellar grains relatively unprocessed by heat.

Type
Part IX. The Primitive Solar Nebula
Copyright
Copyright © A.H. Delsemme 1977

References

Anders, E. 1977, Annual Review Astron. Astrophys., 9, 1.Google Scholar
Cameron, A.G.W. 1973, Space Sci. Reviews, 15, 121.Google Scholar
Delsemme, A. H. 1977, this volume.Google Scholar
Grossman, L. 1977, this volume.Google Scholar
Hoyle, F. 1963, p. 63, in Origin of the Solar System, edit, Jastrow, and Cameron, , Publ. Academic Press, New York.Google Scholar
Huebner, W. 1977, American Astron, Soc, Division Planet. Sci., 8th Meeting, Hawaii, Abstract 094–5, page 25.Google Scholar
Kuiper, G. 1951, p. 357 in Astrophysics: A topical Symposium, edit. Hynek, , Publ. McGraw Hill, New York.Google Scholar
Lambert, 1977, preprint.Google Scholar
Larimer, J. W., and Anders, E. 1970, Geochim. Cosmochim. Acta, 34, 367.Google Scholar
Levine, H. B. 1962, J. Chem. Phys., 36, 3049.Google Scholar
Öpik, E. 1963, p. 73 in Origin of the Solar System, edit. Jastrow, and Cameron, , Publ. Academic Press, New York.Google Scholar
Owen, T., and Cess, R. D. 1975, Astrophys. J. Letters, 197, L37.Google Scholar
Polodak, H. 1976, Icarus, 27, 473.Google Scholar
Ross, J. E., and Aller, L. H. 1976, Science, 191, 1223.Google Scholar
Whipple, F. L. 1950, Astrophys. J., 111, 375.Google Scholar
Whipple, F. L. 1951, Astrophys. J., 113, 464.Google Scholar
Whipple, F. L. 1964, Proc. Nat. Acad. Sci., 51, 711, and 52, 565.CrossRefGoogle Scholar
White, W. B., Johnson, S. M., and Dantzig, G. B. 1958, J. Chem. Phys., 28, 751.Google Scholar