HR: 10:20h
AN: P32A-01    [Abstracts]
TI: 26Al in the Saturnian System - New Interior Models for the Saturnian satellites
AU: * Castillo, J C
EM: Julie.C.Castillo@jpl.nasa.gov
AF: Jet Propulsion Laboratory/CalTech, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Matson, D L
EM: Dennis.L.Matson
AF: Jet Propulsion Laboratory/CalTech, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Johnson, T V
EM: Torrence.V.Johnson
AF: Jet Propulsion Laboratory/CalTech, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Lunine, J I
EM: jlunine@lpl.arizona.edu
AF: Lunar and Planetary Lab., University of Arizona 1629 E. University Blvd, Tucson, AZ 85721 United States
AU: Lunine, J I
EM: jlunine@lpl.arizona.edu
AF: INTA-ISFI, Area di Ricerca Tor Vergata, Rome, 10001 Italy
AU: McCord, T B
EM: mccordtb@aol.com
AF: Planetary Science Institute, 22 Fiddler's Road , Winthrop, WA 98862 United States
AU: Sotin, C
EM: sotin@chimie.univ-nantes.fr
AF: Jet Propulsion Laboratory/CalTech, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Sotin, C
EM: sotin@chimie.univ-nantes.fr
AF: Laboratoire de Planetologie et Geodynamique, 2,rue de la Houssiniere, Nantes, 44322 France
AU: Thomas, P C
EM: thomas@baritone.astro.cornell.edu
AF: Cornell University, Department of Astronomy 422 Space Sciences Building , Ithaca, NY 14853 United States
AU: Turtle, E B
EM: turtle@pirl.lpl.arizona.edu
AF: Lunar and Planetary Lab., University of Arizona 1629 E. University Blvd, Tucson, AZ 85721 United States
AB: Recent study of Iapetus' spin rate evolution highlights the need to form this satellite between between 1.0+/- 0.2 to 1.6+/- 0.4 My after the production of Calcium-Aluminum Inclusions (CAIs). We study the implications of this time constraint on the thermal evolution of other "icy" Saturnian satellites, assuming that they formed at the same time as Iapetus and from the same rocky material in proportion to their densities. Heat provided by 26Al decay contributes to partial to full melting and thus differentiation of all Saturn's medium-sized satellites, except Tethys. We also consider the effect of silicate hydration on the internal and geological evolution of these satellites. These results are compared with classical models (that do not include short-lived radiogenic species), in the light of the observational constraints available for these satellites. Including 26Al decay in the heat budget of the satellites allows to explain the observation of geological activity in silicate-poor satellites such as Tethys. We note that in Enceladus and Titan conditions might have been such that the boiling point of water was reached and water might have been lost very early in the history of these satellites. This opens the door to some explanation for the variations in density within the Saturnian system. Part of this work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA.
DE: 3616 Hydrothermal systems (0450, 1034, 3017, 4832, 8135, 8424)
DE: 5450 Orbital and rotational dynamics (1221)
DE: 5455 Origin and evolution
DE: 8147 Planetary interiors (5430, 5724, 6024)
DE: 8160 Rheology: general (1236, 8032)
SC: Planetary Sciences [P]
MN: Fall Meeting 2005