Lecture 40: The Saturn System
Saturn is attended by a system of 56 known moons and bright, beautiful\nrings. The Moon system is the focus of our attention today. Saturn has\none giant moon, Titan, which is the 2nd largest moon in the Solar\nSystem, and the only one with a heavy atmosphere. On Titan, the\natmosphere is mostly nitrogen and methane, but the temperature and\npressure are such that methane plays the same role that water plays on\nthe Earth: it can be either a solid, gas, or liquid. I will review\ntantalizing evidence from the Cassini and Huygens probes that there is,\nin fact, liquid methane and maybe even liquid methane lakes on Titan.\nMost of the other moons are ancient, icy, and heavily cratered -\ngeologically dead worlds - but one, Enceladus, is a big surprise. The\nshiniest object in the Solar System, Enceladus has spectacular fountains\n- cryovolcanos - that spew water vapor from reservoirs created in its\ntidally-heated interior. This ice repaves much of the surface of\nEnceladus, giving it a young, shiny surface, and builds the E ring of\nSaturn. Recorded 2006 Nov 21 in 100 Stillman Hall on the Columbus\ncampus of The Ohio State University.