HR: 11:50h
AN: P32A-07    [Abstracts]
TI: The Enceladus Neutral Cloud and the OH Torus
AU: * Johnson, R E
EM: rej@virginia.edu
AF: university of virginia, thornton hall B103, charlottesville, VA 22902 United States
AU: Burger, M
P32A-07 AF: goddard space flight center, Greenbelt road, Greenbelt, MD 20771 United States
AU: Sittler, E C
P32A-07 AF: goddard space flight center, Greenbelt road, Greenbelt, MD 20771 United States
AU: Richardson, J D
P32A-07 AF: Massachusettes Institute of Technology, Cambridge Rd, Cambridge, MA 02139 United States
AU: Jurac, S
P32A-07 AF: Massachusettes Institute of Technology, Cambridge Rd, Cambridge, MA 02139 United States
AB: Following the discovery of venting of water vapor from Enceladus, we examined the contribution of this source to the neutral OH torus that was observed by HST. Preliminary analysis of Cassini data suggest that the Enceladus source rate is comparable to the `missing source' (~10e27-10e28 H2O/s; Jurac et al. 2002; Jurac and Richardson 2005) required to explain the HST observations. However, the radial distribution of the OH torus and the Enceladus neutral cloud differ considerably, unless one includes the interaction of the Enceladus cloud with the ambient plasma and/or accounts for water molecules ejected from the emitted grains. Here we describe the emission of water vapor from Enceladus, the formation of its neutral cloud and its redistribution by charge exchange (Johnson et al. 2005). We also examine the emitted grains as a potential source of water vapor at some distance from Enceladus. We compare the resulting Enceladus cloud to the most recent model for the OH torus observed by HST. R.E. Johnson et al. G.R.L. submitted, 2005 S. Jurac et al G.R.L. 29, no. 24, 2172, doi:10.1029/2002GL0158S, 2002. S. Jurac and J.D. Richardson, J.G.R. in press, 2005
DE: 5737 Magnetospheres (2756)
DE: 5759 Rings and dust
DE: 6280 Saturnian satellites
SC: Planetary Sciences [P]
MN: Fall Meeting 2005