Large craters on small objects: Occurrence, morphology, and effects

Authors
Citation
Pc. Thomas, Large craters on small objects: Occurrence, morphology, and effects, ICARUS, 142(1), 1999, pp. 89-96
Citations number
44
Categorie Soggetti
Space Sciences
Journal title
ICARUS
ISSN journal
00191035 → ACNP
Volume
142
Issue
1
Year of publication
1999
Pages
89 - 96
Database
ISI
SICI code
0019-1035(199911)142:1<89:LCOSOO>2.0.ZU;2-8
Abstract
Spacecraft imaging data allow an accounting of the occurrence and character istics of the largest craters on small asteroids and satellites. Data cover ing Phobos, Deimos, Gaspra, Ida, Mathilde, Vesta, Amalthea, Thebe, Janus, E pimetheus, Hyperion, and Proteus show that similar to 50% of rocky objects support craters with diameters of 1 object mean radius (R-m), and the great majority have more than two craters with D > 0.5R(m). The morphology of th ese craters is consistent with gravity (g(-1)) scaling from craters on larg er objects, The amounts of visible peripheral damage, such as fracturing ca used by these relatively large impacts, are usually small; the best possibl e example (Phobos) may have been assisted by tidal forces. The occurrence a nd characteristics of these craters supports modeling results that predict formation in gravity-controlled regimes with very large relative-sized crat ers formed before global fragmentation occurs. (C) 1999 Academic Press.