HR: 16:30h
AN: P14A-05    [Abstracts]
TI: Saturn's Planetary Magnetic Field: Cassini In-orbit Observations
AU: * Smith, E J
EM: edward.j.smith@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 48oo Oak Grove Dr., Pasadena, CA 91109 United States
AU: Giampieri, G
EM: giacomo.giampieri@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 48oo Oak Grove Dr., Pasadena, CA 91109 United States
AU: Dougherty, M K
EM: m.dougherty@imperial.ac.uk
AF: Imperial College, Prince Consort Rd., London, Sw7 2 AZ United Kingdom
AU: Russell, C T
EM: ctrussel@igpp.ucla.edu
AF: University of California Los Angeles, 595 Charles Young Drive East, Los Angeles, CA 90024 United States
AB: Insertion of Cassini into orbit approximately one year ago produced the equivalent of another close flyby of Saturn after a lapse of 23 years. Field measurements within 1.3 radii reconfirmed the remarkable axial symmetry of the field and showed that little, if any, secular change had occurred since the earlier Pioneer 11 and Voyager 1 and 2 flybys. Observations of the planetary field have continued during the in-orbit phase of the mission. Over half a dozen additional periapses have occurred including one with a closest approach of 2.6 Saturn radii. Although operational problems prevented the acquisition of scalar magnetic field data at SOI, subsequent periapses provide additional opportunities to obtain highly accurate measurements of the field magnitude. These accumulating vector- and scalar measurements enable further investigation of various aspects of the planetary field. Investigation continues of intermittent field variations with quasi-periods near the planetary rotation period that would not normally be expected for an axially symmetric field. A possible cause is a "magnetic anomaly" in Saturn's field that is revealed during "special" circumstances. Alternatively, shielding of the non- axially symmetric components hypothesized by Stevenson could be less efficient at high latitudes in which case a tilt angle and periodicity of the core could become evident with increasing latitude or possibly in the outer magnetosphere.
DE: 5719 Interactions with particles and fields
DE: 5724 Interiors (8147)
DE: 5734 Magnetic fields and magnetism
DE: 5737 Magnetospheres (2756)
SC: Planetary Sciences [P]
MN: 2005 Joint Assembly