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8. Asteroid Versus Comet Discrimination from Orbital Data
Published online by Cambridge University Press: 12 April 2016
Abstract
The orbital comet-asteroid criteria, their premises, dynamical reasoning, and ranges of applicability are reviewed. Mapping of all known comets and asteroids in a plane of energy intergral in the two body problem (1/a) vs. that in the restricted three-body problem (Tisserand invariant) is presented. The potential evolutionary paths from different sources of active comets into short-period orbits are delineated and interfaced with the process of reducing the perihelion distances of the asteroids. The significance of resonances with Jupiter is emphasized. Statistics of observed close approaches of individual comets and asteroids to the Earth is analyzed to estimate their relative fluxes. Active cometary nuclei are found to represent about 1/8 of the flux of objects with radii exceeding 1 km in the vicinity of the Earth, and their contribution tends to diminish significantly for still smaller bodies. However, there is no evidence against comets leaving inactive asteroid-like nuclei with considerable lifetimes which may represent a significant, though secondary, source of meteors and even meteor streams. An overwhelming majority of the Apollo and Amor objects are suggested to be of asteroidal nature; the most probable exceptions are selected and recommended for detailed observation.
- Type
- Part V. Orbital Evolution and Fragmentation of Asteroids
- Information
- International Astronomical Union Colloquium , Volume 39: Comets, Asteroids, Meteorites: Interrelations, Evolution and Origins , December 1977 , pp. 313 - 321
- Copyright
- Copyright © A.H. Delsemme 1977
References
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