The physics of planetary rings

A review of the collisional, collective, and resonance phenomena in planetary rings is presented. The following questions are examined: the reasons for the existence of planetary rings and the properties of a typical particle, the collisional breaking of loose bodies, and the azimuthal asymmetry effect for the rings of Saturn. A transfer theory is being developed for differentially rotating disks of inelastic particles, and the collective instabilities of planetary rings and a protoplanetary disk are discussed. A model for the resonance origin for the rings of Uranus is described, which enabled one to predict unknown satellites of Uranus that were later discovered by “Voyager-2”. The problem of the stability of the rings of Uranus is examined.