Abstract
The basic geochemical model of the structure of the Moon proposed by Anderson, in which the Moon is formed by differentiation of the calcium, aluminium, titanium-rich inclusions in the Allende meteorite, is accepted, and the conditions for formation of this Moon within the solar nebula models of Cameron and Pine are discussed. The basic material condenses while iron remains in the gaseous phase, which places the formation of the Moon slightly inside the orbit of Mercury. Some condensed metallic iron is likely to enter the Moon in this position, and since the Moon is assembled at a very high temperature, it is likely to have been fully molten, so that the iron can remove the iridium from the silicate material and carry it down to form a small core. Interactions between the Moon and Mercury lead to the present rather eccentric Mercury orbit and to a much more eccentric orbit for the Moon, reaching past the orbit of the Earth, establishing conditions which are necessary for capture of the Moon by the Earth. In this orbit the Moon, no longer fully molten, will sweep up additional material containing iron oxide. This history accounts in principle for the two major ways in which the bulk composition of the Moon differs from that of the Allende inclusions.
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Anderson, D. L.: 1972, Nature239, 263.
Anderson, D. L.: 1973, ‘The Internal Constitution of the Moon’, to be published inproc. IAGC Cosmochemistry Symposium, Cambridge, Mass., 1972.
Cameron, A. G. W.: 1970,EOS, Trans. Am. Geophys. Union 51, 628.
Cameron, A. G. W.: 1972,Nature 240, 299.
Cameron, A. G. W.: 1973,Icarus, in press.
Cameron, A. G. W. and Pine, M. R.: 1973,Icarus, in press.
Ezer, D., and Cameron, A. G. W.: 1965,Can. J. Phys. 43, 1497.
Gast, P. W.: 1972, ‘The Chemical Composition and Structure of the Moon’, in press.
Hayashi, C.: 1966,Ann. Rev. Astron. Astrophys. 4, 171.
Hayashi, C., Hoshi, R., and Sugimoto, D.: 1962,Prog. Theor. Phys. Suppl., No. 22.
Kaula, W. M.: 1971,Rev. Geophys. Space Phys. 9, 217.
Larson, R. B.: 1969,Monthly Notices Roy. Astron. Soc. 145, 271.
Lewis, J. S.: 1972,Earth Planetary Sci. Letters 15, 286.
O'Keefe, J. A.: 1970,EOS, Trans. Am. Geophys. Union 51, 633.
Perri, F. and Cameron, A. G. W.: 1973, ‘The Hydrogen Flash in Stars’, to be published.
Ringwood, A. E.: 1970,Earth Planetary Sci. Letters 8, 131.
Singer, S. F.: 1970,EOS, Trans. Am. Geophys. Union 51, 637.
Urey, H. C.: 1959,J. Geophys. Res. 64, 1721.
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Paper dedicated to Professor Harold C. Urey on the occasion of his 80th birthday on 29 April 1973.
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Cameron, A.G.W. Properties of the solar nebula and the origin of the moon. The Moon 7, 377–383 (1973). https://doi.org/10.1007/BF00564641
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DOI: https://doi.org/10.1007/BF00564641