THE REMOTE SENSING OF SATURN'S RINGS I:The Magnetic Alinement of the Ring Particles

摘要

Because of the potential implications for the optical properties of Saturn's rings, the orientation of non-spherical ring particles at equilibrium is investigated with respect to four stochastic influences: interactions with the interplanetary medium, interactions with the expected magnetic field of Saturn, thermal fluctuations due to the internal temperature of the ring particles; and collisions between ring particles. The solution of the homogeneous Fokker-Planck equation for nearly spherical spheroids is presented and investigated in general. Values of the pertinent physical parameters in the vicinity of Saturn are estimated, and the implications for the alinement of the ring particles are investigated. It is concluded that for some alinement mechanisms, small ring particles (size < 10 cm) can be expected to be almost completely alined (a < 1°). This alinement results in each particle spinning around its shortest body axis with this axis parallel to the magnetic field direction (perpendicular to the ring plane).