COLLISIONAL HISTORY OF GASPRA

Citation
R. Greenberg et al., COLLISIONAL HISTORY OF GASPRA, Icarus, 107(1), 1994, pp. 84-97
Citations number
23
Categorie Soggetti
Astronomy & Astrophysics
Journal title
IcarusACNP
ISSN journal
00191035
Volume
107
Issue
1
Year of publication
1994
Pages
84 - 97
Database
ISI
SICI code
0019-1035(1994)107:1<84:CHOG>2.0.ZU;2-#
Abstract
Interpretation of the impact record on Asteroid 951 Gaspra requires un derstanding of the effects of collisions on a target body of Gaspra's size and shape. Recent hydrocode models show that major impacts on Gas pra may leave craters larger than previously thought possible and that they can create substantial regolith and produce global jolting capab le of erasing many smaller craters. A Gaspra-size body has a mean life time of about 10(9) years and is likely to have several impact craters of 4 km diameter or larger, which is consistent with the number of ob served concavities on Gaspra. The steep size distribution of small cra ters on Gaspra implies an even steeper distribution for small asteroid s, and the relative paucity of kilometer-size craters seems to require a twice-in-a-Gaspra-lifetime impact to have occurred about 50 myr ago . All of these considerations consistently point to a scenario in whic h several of the very large concavities (>4 km diameter) on Gaspra are probably impact craters. (C) 1994 Academic Press, Inc.