Hostname: page-component-cd9895bd7-gvvz8 Total loading time: 0 Render date: 2024-12-23T16:15:42.077Z Has data issue: false hasContentIssue false
  • English
  • Français

The origin of comets among the accreting outer planets

Published online by Cambridge University Press:  12 April 2016

Richard Greenberg
Richard Greenberg*
Affiliation:
Planetary Science Institute, 2030 E. Speedway, Suite 201, Tucson, Arizona 85719, USA

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The hypothesis of formation of comets as an accompaniment to formation of Uranus and Neptune from icy planetesimals is attractive for several reasons, but has suffered from long-standing problems regarding formation of the planets themselves. The history of this problem is reviewed, and recent results are described that may help solve it. Numerical simulations of planet growth show that when the system of planetesimals is no longer artificially constrained to a power-law size distribution, growth of planets may occur in reasonable time. An adeguate number of comet-sized bodies to populate the Oort cloud is not produced as collisional debris during the planet-building process. Rather, the comets are probably a remnant of the original planetesimal “building blocks” from which the planets grew.

Type
Section I. Origin of Comets
Information
International Astronomical Union Colloquium , Volume 83: Dynamics of Comets: Their Origin and Evolution , 1985 , pp. 3 - 10
Copyright
Copyright © Cambridge University Press 1985

References

Fernandez, J.A., and Ip, W.H. (1981). ‘Dynamical evolution of a cometary swarm in the outer planetary region’, Icarus 47, 470–479.Google Scholar
Goldreich, P., and Ward, W.R. (1973). ‘The formation of planetesimals’. Astrophys. J. 183, 1051.Google Scholar
Greenberg, R., Wacker, J.F., Hartmann, W.K., and Chapman, C.R. (1978). ‘Planetesimals to planets: Numerical simulation of collisional evolution’, lcarus 35, 1–26.Google Scholar
Greenberg, R., Weidenschilling, S.J., Chapman, C.R. (1984). ‘From icy planetesimals to outer planets and comets’. Icarus 59, 87–113.CrossRefGoogle Scholar
Hartmann, W.K. (1969). ‘Terrestrial, lunar, and interplanetary fragmentation’, Icarus 10, 201–213.CrossRefGoogle Scholar
Levin, B.J. (1972). ‘Revision of initial size, mass, and angular momentum of the solar nebula and the problems of its origin’, in The Origin of the Solar System (Reeves, H., Ed.), CNRS, Paris.Google Scholar
Levin, B.J. (1978). ‘Relative velocities of planetesimals and the early accumulation of planets’, Moon and Planets 19, 289–296. CrossRefGoogle Scholar
Opik, E.J. (1973). ‘Comets and the formation of planets’, Astrophys. Space Sci. 21, 307–398.CrossRefGoogle Scholar
Safronov, V.S. (1969). Evolution of the Protoplanetary Cloud and Formation of the Earth and the Planets, Nauka Publ., Moscow, English translation: NASA TT F-677 (1972).Google Scholar
Safronov, V.S. (1972). ‘Accumulation of the planets’, in Origin of the Solar System (Reeves, H., Ed.), CNRS, Paris, 89–113.Google Scholar
Safronov, V.S. (1977a). ‘Oorts cometary cloud in the light of modern cosmogony’, in Comets. Asteroids. and Meteorites (Delsemme, A., Ed.), Univ. of Toledo Press, 483–484.Google Scholar
Safronov, V.S. (1977b). ‘Time scale for the formation of the Earth and planets and its role in their geochemical evolution’, in Soviet-American Conference on Cosmochemistry of the Moon and Planets, NASA SP–370.Google Scholar
Safronov, V.S., and Ruskol, E.L. (1982). ‘On the origin and initial temperature of Jupiter and Saturn’, Icarus 49, 284–296.Google Scholar