DPS Pasadena Meeting 2000, 23-27 October 2000 Session 48. Rings
Oral, Chairs: P. Nicholson, A. Bosh, Friday, 2000/10/27,
8:30-10:00am, Little Theater (C107)  [Previous] | [Session 48] |
[Next]  [48.06] Marginal Gravitational Stability and Viscous
Transport in Saturn's A Ring  G.R. Stewart (Univ. of Colorado)
Recurrent local gravitational instabilities in the outer
portions of Saturn's rings tend to form hundred-meter-scale
``wakes" that are believed to cause the observed azimuthal
brightness asymmetry in the rings. Local N-body simulations of
planetary rings show that such structures readily form and can
greatly enhance the rate of viscous angular momentum transport
in the rings. Numerical calculations of the rate of momentum
transport closely match an analytic estimate derived by Ward and
Cameron (1978) to describe the viscous evolution of the
protolunar disk formed by a giant impact on the protoearth. An
outstanding puzzle, however, is why the amplitude of the
brightness asymmetry peaks in the middle of th