Abstract
It is generally supposed that the atmospheres of the terrestrial planets were formed by secondary degassing processes. We propose, instead, that they are of primary origin, forming as an immediate and necessary consequence of the final stages of planetary accretion. Once the planetary embryo reached a critical size, the impacting material began to vaporize. The atmosphere, so created, then decelerated other impacting material, thus limiting the rate of atmospheric growth. We show that, given reasonable assumptions concerning the chemical composition of the impacting material, an acceptable model for the early atmosphere of the Earth, and the present atmospheres of Venus and Mars results.
A discussion of the noble gas data for the terrestrial atmosphere indicates that these can be readily reconciled with an impact origin.
Similar content being viewed by others
References
Ahrens, T. J. and O'Keefe, J. D.: 1972,The Moon,4, 214–249.
Anders, E.: 1971,Ann. Rev. Astron. Astrophys. 9, 1–34.
Arrhenius, G., De, B. R., and Alfvén, H.: 1974, in E. D. Goldberg (ed.),The Sea, Vol. 5, Wiley, pp. 839–861.
Black, D. C.: 1972,Geochim. Cosmochim. Acta 36, 377–394.
Black, D. C. and Pepin, R. O.: 1969,Earth Planet Sci. Lett. 6, 395–405.
Cameron, A. G. W.: 1973,Icarus 18, 407–450.
Canalas, R. A., Alexander, E. C., Jr., and Manuel, O. K.: 1968,J. Geophys. Res. 73, 3331–3334.
Delsemme, A. H.: 1976, private communication.
Fanale, F. P. and Cannon, W. A.: 1972,Geochim. Cosmochim. Acta 36, 319–328.
Fisher, D. E.: 1974,Geophys. Research Lett. 1 161–164.
Goody, R. M. and Walker, J. C. G.: 1972,Atmospheres, Foundations of Earth Science Series, Prentice-Hall Inc.
Gregor, B.: 1972,24th Internal. Geol. Congress Montreal, Section 10, 36.
Jeffrey, P. M. and Anders, E.: 1970,Geochim. Cosmochim. Acta 34, 1175–1198.
Meadows, A. J.: 1972,Physics Reports (C)5, 197–236.
Ozima, M.: 1975,Geochim. Cosmochim. Acta 39, 1127–1134.
Ronov, A. B. and Yaroshevsky, A. A.: 1967,Geochem. Internat. 4, 1041–1061.
Studier, M. H., Hayatsu, R., and Anders, E.: 1968,Geochim. Cosmochim. Acta 32, 151–173.
Studier, M. H., Hayatsu, R., and Anders, E.: 1972,Geochim. Cosmochim. Acta 36, 189–215.
Turekian, K. K. and Clark, S. P., Jr.: 1975,J. Atmos. Sci. 32, 1257–1261.
Vedder, J. F.: 1966,Space Sci. Rev. 6, 365–414.
Walker, J. C. G.: 1975,J. Atmos. Sci. 32, 1248–1256.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Benlow, A., Meadows, A.J. The formation of the atmospheres of the terrestrial planets by impact. Astrophys Space Sci 46, 293–300 (1977). https://doi.org/10.1007/BF00644376
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00644376