Energy Loss and Aggregation Processes in Low Speed Collisions of Ice Particles Coated with Frosts or Methanol/Water Mixtures

Abstract

At low speeds, the energy loss in collisions and the adhesion (sticking) between particles depends strongly on the surface layer composition and morphology. In this paper we review our measurements of the coefficient of restitution in low speed collisions for a variety of surface coatings, for speeds in the range 0.01- 2 cm/s, and also the investigations of sticking forces (under both dynamic and static conditions), including the conditions for which sticking contacts have been observed. These results are compared with a few other similar measurements, and with theoretical models for energy loss in collisions. Specific applications to the dynamics of Saturn’s rings and to the formation of planetesimals in the early solar nebula, which motivated these studies, are also discussed.