An Explanation of the Frequent Occurrence of Commensurable Mean Motions in the Solar System

Abstract

In this paper a tidal origin of commensurable satellite mean motions is proposed. It is shown that special cases of commensurate mean motions are not disrupted by tidal forces. Furthermore, at least four, and probably seven, of the best examples of commensurabilities have this stability. The significance of these stable configurations to the evolution of satellite systems is discussed and some inferences are drawn about tidal dissipation in Jupiter and Saturn.