THE EFFECT OF NONCONSERVATIVE FORCES ON RESONANCE LOCK - STABILITY AND INSTABILITY

Resonance lock, when a nonconservative force is present, may have a stable or an unstable character. We investigate which kinds of force yield stability and which yield instability, for any exterior resonance. We develop an analytical model, through which a criterion for stability is established. This criterion is checked by numerical integrations of the complete equations of motion with a conveniently chosen fictitious nongravitational force. Real nonconservative forces that have been acting in the present and past Solar System are analyzed in view of the deduced criterion. This explains the more stable character of resonance locks with gas drag and also the unstable character of resonance locks with forces induced by solar radiation and solar wind. (C) 1995 Academic Press, Inc.