Saturn is attended by a system of 56 known moons and bright, beautiful
rings. The Moon system is the focus of our attention today. Saturn has
one giant moon, Titan, which is the 2nd largest moon in the Solar
System, and the only one with a heavy atmosphere. On Titan, the
atmosphere is mostly nitrogen and methane, but the temperature and
pressure are such that methane plays the same role that water plays on
the Earth: it can be either a solid, gas, or liquid. I will review
tantalizing evidence from the Cassini and Huygens probes that there is,
in fact, liquid methane and maybe even liquid methane lakes on Titan.
Most of the other moons are ancient, icy, and heavily cratered -
geologically dead worlds - but one, Enceladus, is a big surprise. The
shiniest object in the Solar System, Enceladus has spectacular fountains
- cryovolcanos - that spew water vapor from reservoirs created in its
tidally-heated interior. This ice repaves much of the surface of
Enceladus, giving it a young, shiny surface, and builds the E ring of
Saturn. Recorded 2006 Nov 21 in 100 Stillman Hall on the Columbus
campus of The Ohio State University.