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Capture of planetesimals into a circumterrestrial swarmThe lunar origin model considered involves processing of protolunar material through a circumterrestrial swarm of particles. Once such a swarm has formed, it can gain mass by capturing infalling planetesimals and ejecta from giant impacts on the Earth, although the angular momentum supply from these sources remains a problem. Examined is the first stage of formation of a geocentric swarm by capture of planetesimals from initialy heliocentric orbits. The only plausible capture mechanism that is not dependent on very low approach velocities is the mutual collision of planetesimals passing within Earth's sphere of influence. This capture scenario was tested directly by many body numerical integration of planetesimal orbits in near Earth space. Results agree that the systematic contribution of angular momentum is insufficient to maintain an orbiting swarm under heavy bombardment. Thus, a circumterrestrial swarm can be formed rather easily, but is hard to sustain because the mean net angular momentum of a many body swarm is small.
Document ID
Document Type
Conference Paper
Weidenschilling, S. J. (Planetary Science Inst. Tucson, AZ, United States)
Date Acquired
August 12, 2013
Publication Date
January 1, 1984
Publication Information
Publication: Lunar Planetary Inst. Conf. on the Origin of the Moon
Subject Category
Distribution Limits
Work of the US Gov. Public Use Permitted.

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IDRelationTitle19850005400Analytic PrimaryConference on the Origin of the Moon