"Enceladus: An Active Ice World"
Professor John Spencer (Southwest Research Institute)
340 WH on Thursday September 27th from 4-5pm
The Saturn-orbiting Cassini spacecraft has discovered ongoing geological activity on Saturn's small (500 km diameter) moon Enceladus, making it the only known active icy body in the solar system. Tidally-generated heat powers a series of jets of ice particles, water vapor, and other gases issue from warm fractures close to Enceladus' south pole. Much of the gas and dust is ejected at speeds exceeding Enceladus' escape velocity, producing a dust and gas cloud that dominates Saturn's middle magnetosphere. Many questions remain about the nature of the tidal heat engine, the mechanism that produces the jets, and in particular about the possibility of liquid water, and other requirements for life, in the interior of Enceladus. A series of eight more flybys of Enceladus by the richly-instrumented Cassini spacecraft may provide answers to some of these questions.