Dynamical lifetimes and final fates of small bodies: Orbit integrations vsOpik calculations

Citation
L. Dones et al., Dynamical lifetimes and final fates of small bodies: Orbit integrations vsOpik calculations, ICARUS, 142(2), 1999, pp. 509-524
Citations number
97
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Space Sciences
Journal title
ICARUS
ISSN journal
0019-1035 → ACNP
Volume
142
Issue
2
Year of publication
1999
Pages
509 - 524
Database
ISI
SICI code
0019-1035(199912)142:2<509:DLAFFO>2.0.ZU;2-U
Abstract
The dynamical lifetimes of small bodies against ejection from the Solar Sys tem or collision with the Sun or a planet are often estimated by Monte Carl o codes based on the equations of Opik and using a method implemented by Ar nold. Such algorithms assume that orbital changes are dominated by close en counters, and that successive encounters are uncorrelated, We have compared the results of an Opik code (H. J. Melosh and W. B, Tonks, Meteoritics 28, 398 (1993)) and a fast integrator (H, F. Levison and M, J, Duncan, Icarus 108, 18 (1994)) to investigate the regimes of validity of the Opik-Arnold a pproach, We investigate the transfer of ecliptic comets from Neptune-crossi ng orbits to observable Jupiter-family comets, the dynamics of Halley-type comets, and the transport of meteorites among the terrestrial planets, In a ll cases, the Opik code overestimates the median lifetime of the small bodi es, although both codes show a rapid initial loss of objects followed by a slow decay, For martian impact ejecta, some of which find their way to Eart h as the SNC meteorites, the Opik code substantially overestimates lifetime s because of its neglect of secular resonances, which rapidly pump eccentri cities (B, J, Gladman ed at, Science 271, 1387 (1996)). (C) 1999 Academic P ress.