Tiscareno, M.S. and the Cassini Imaging Team (2008). "Saturn's Rings: An Accessible Astrophysical Disk." American Astronomical Society, 211th meeting, #39, #109.06.


Abstract
Saturn's ring system is an astrophysical disk that is neither light-years away nor billions of years in the past. We can visit this disk at close range and observe a number of phenomena that also operate in disks of other kinds. As a result, we see small-scale processes that shape ring texture, connect those processes to the bodies and structures that cause them, and watch closely as the disk changes with time.

Recent observations include: 1) 'self-gravity wakes' (see Julian and Toomre 1966) dominating the texture of some ring regions; 2) km-sized 'propeller-shaped' features caused by small (100-meter) moonlets embedded in the disk; 3) irregular edge shapes in the gaps opened up by larger (~10 km) moons, which may hold clues to angular momentum transport; 4) resonant spiral density waves excited by more distant large moons, which serve as in situ probes of local disk density and viscosity; 5) waves whose form changes with time, due to the varying orbits of the moons Janus and Epimetheus. The latest results from the Cassini mission will be presented.