HR: 11:15h
AN: P52A-04    [Abstracts]
TI: The Dynamic Atmosphere of Enceladus Revealed by Magnetometer Observations
AU: * Khurana, K K
EM: kkhurana@igpp.ucla.edu
AF: Institute of Geophysics and Planetary Physics, UCLA, Los Angeles, CA 90095 United States
AU: Dougherty, M K
P52A-04 AF: Imperial College, Department of Physics, London, SW72AZ United Kingdom
AU: Travnicek, P
P52A-04 AF: Institute of Atmospheric Physics, Czech Academy of Sciences, Prague, 4 Czech Republic
AU: Neubauer, F M
P52A-04 AF: Institute fur Geophysik und Meterologie, University of Cologne, Cologne, 50374 Germany
AU: Saur, J
P52A-04 AF: Institute fur Geophysik und Meterologie, University of Cologne, Cologne, 50374 Germany
AU: Russell, C T
P52A-04 AF: Institute of Geophysics and Planetary Physics, UCLA, Los Angeles, CA 90095 United States
AB: The three close flybys of Enceladus in 2005 by Cassini have provided a wealth of new information on the interaction of Enceladus with the Saturnian magnetospheric plasma. These flybys show that the tiny icy moon (radius 250 km) presents itself as a large obstacle to the plasma flow. All three Enceladus encounters occurred on the upstream side of Enceladus at closest approach distances of 5.8, 3.0 and 1.7 Enceladus radii (RE) respectively. Because Enceladus is located very close to the equatorial plane of Saturn, the plasma density of the corotating Saturnian plasma is quite high and exceeds 60 ions/cm3. The three flybys show that the obstacle is not co-located with Enceladus but is displaced at least one RE south of Enceladus. Further modeling of the signature reveals that the effective obstacle is at least 2 RE in radius and its characteristics (size, conductivity and location) show variations between passes. These results can be modeled using an effective conductivity arising from a plume generated dynamic atmosphere which is confined mainly to the southern hemisphere of Enceladus. The results of the modeling study will be interpreted in context with the observations of the neutral atmosphere obtained from the remote sensing instruments during the E11 flyby.
DE: 1060 Planetary geochemistry (5405, 5410, 5704, 5709, 6005, 6008)
DE: 6026 Ionospheres (2459)
DE: 6280 Saturnian satellites
SC: Planetary Sciences [P]
MN: Fall Meeting 2005