HR: 13:40h
AN: U23A-01 INVITED     [Abstracts]
TI: Cassini-Huygens at Saturn --- A Grand Exploration of the Saturnian System
AU: * Matson, D L
EM: dmatson@jpl.nasa.gov
AF: Jet Propulsion Laboratory , 4800 Oak Grove Drive, Pasadena, CA 91106 United States
AU: Lebreton, J
EM: Jean-Pierre.Lebreton@rssd.esa.int
AF: ESTEC/RSSD Planetary Mission Division, Keplerlaan 1, Norordwijk, 2200 AG Netherlands
AU: Spilker, L
EM: Linda.J.Spilker@jpl.nasa.gov
AF: Jet Propulsion Laboratory , 4800 Oak Grove Drive, Pasadena, CA 91106 United States
AB: The Cassini-Huygens spacecraft was placed in an orbit about Saturn on June 30, 2004. By this time much had already been accomplished. There was a very successful campaign during the flyby of Jupiter. There was a joint HST/Cassini campaign to observe Saturn's aurorae. Major discoveries started at Phoebe, a distant satellite and Cassini-Huygens' first "contact" with the Saturnian system. Phoebe dazzled us with its morphology and the compositionally variegated surface. Next, the spacecraft entered the magnetosphere several days sooner than expected because it was more inflated than during the Voyager flybys. Cassini-Huygens passed through the rings, and fired an engine to achieve orbit around Saturn, skimming just above the rings, crossing through the ring plane just outside the main rings. At that time unique observations of the rings and of the planet's magnetic field were obtained. A new radiation belt was discovered between the innermost ring and the planet. The dust and Magnetospheric plasma interaction with the satellite Enceladus is very interesting and much material from that satellite appears to be loading the magnetosphere. It may have a tenuous, localized atmosphere. This together with an observed South Polar thermal anomaly is suggestive of ongoing activity. Satellites are of key interest because they record history, much of which can be deciphered by study of impact craters on their surfaces. Iapetus, in addition to its strange albedo distribution, has a unique geophysical signature which appears to constrain the age of the system. Saturn has distinguished itself by indicating a different magnetic rotation period than that recorded by Voyager. Its rotation and magnetic axis are precisely aligned. Large atmospheric storms are sources of immense lightening displays and correlated electromagnetic emissions. The magnificent rings have not disappointed us. New structures and processes have been discovered. The rings show a range of composition that is baffling to explain. Ah, not to forget mysterious Titan. Morphologically it resembles the Earth's surface in many ways. But, where is the liquid that carved the "stream channels"? Fortunately, there will be more flybys of Titan and more will be learned. Highlights of the many discoveries in all aspects of the Saturnian system will be presented. The Huygens mission at Titan is described in the following paper. Cassini-Huygens is a joint NASA-ESA program in cooperation with ASI.
DE: 6275 Saturn
DE: 6280 Saturnian satellites
SC: Union [U]
MN: Fall Meeting 2005