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N.N. Gorkavyi (Greenwich Institute for Science and Technology)
The new model explains origin of the Moon, the Charon and binary asteroids without catastrophic events. Basic elements of new model: 1. Most of Moon material was delivered from Earth mantle by many impacts of large (~1-100 km) asteroids. This explains "low-iron" composition of the Moon as in Hartmann-Davis single-impact model. 2. Initial low-mass prograde protosatellite disk was collected around the proto-Earth as near other planets. 3. Collisions of Earth debris with particles of prograde protosatellite disk is key factor for collection of debris on stable orbits. Easy to show that prograde Earth debris effectively joined to prograde protosatellite disk vs. retrograde debris that returned to Earth. Due to prograde Earth rotation volume of prograde debris is larger than retrograde debris volume. 4. Calculations of ballistic transfer of angular moment (A.M.Fridman, N.N.Gorkavyi "Physics of Planetary Rings", Springer, 1999, p.222-233) show that protosatellite ring must have the optimal radius that is close to average semi-major axis of debris orbits: Earth debris push away a smaller ring and decrease moment of larger ring. 5. Massive low-iron ring near Earth accreted to the Moon. At final stage, Earth debris bombarded new-born Moon, that shows dichotomy of crater populations. Predictions from new multi-impacts model: a. Most of satellites of asteroids must have prograde and circular orbits that close to equator of central body (as in Moon-Earth and Charon-Pluto systems); b. Asteroids with satellites must have faster rotation than single asteroids; c. Most low rotate asteroids (or earth-like planets) have not satellites (as Venus and Mercury); d. For same other conditions, relative mass of satellites can be larger for smaller asteroids; e. Crater’ dichotomy must be typical for the Charon, the Pluto itself and large satellites of asteroids; f. the Moon must have chemical, isotopic and geological signatures of many different impacts of asteroids to the Earth.
The author(s) of this abstract have provided an email address for comments about the abstract: simeiz@aol.com
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Bulletin of the American Astronomical Society, 36 #2
© 2004. The American Astronomical Soceity.