Cratering rate over the surface of a synchronous satellite

Abstract

Equations have been derived for the asymmetries of crater frequency over the surface of a synchronously rotating satellite, when the orbital velocities of projectiles about the parent planet are always larger than the satellite's circular orbital velocity. If the projectiles orbit the planet in moderately eccentric ellipses, no marked apex-antapex asymmetries of crater frequency distribution are expected. Theoretical values of apex-antapex asymmetries are presented for the Earth, the Moon, and some Jovian and Saturnian satellites, and are compared with available observational and theoretical results.