Plasma Near Saturn's Rings: CAPS observations

HR: 09:20h
AN: P51C-07 INVITED [Abstracts]
TI: Plasma Near Saturn's Rings: CAPS observations
AU: Young, D T
EM: dyoung@swri.edu
AF: Southwest Research Institute, P.O. Drawer 28510, San Antonio, TX 78228-0510 United States
AU: * Coates, A J
EM: ajc@mssl.ucl.ac.uk
AF: Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, RH5 6NT United Kingdom
AU: McAndrews, H J
EM: hjm@mssl.ucl.ac.uk
AF: Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, RH5 6NT United Kingdom
AU: Crary, F J
EM: fcrary@swri.edu
AF: Southwest Research Institute, P.O. Drawer 28510, San Antonio, TX 78228-0510 United States
AU: Maurice, S
EM: maurice@obs-mip.fr
AF: Observatoire Midi-PyrenＦs, 14, Avenue Edouard Belin, Toulouse, 31400 France
AU: Johnson, R E
EM: rej@virginia.edu
AF: University of Virginia, Engineering Physics, Thornton Hall, Charlottesville, VA 22904 United States
AU: Baragiola, R
EM: rb9a@virginia.edu
AF: University of Virginia, Engineering Physics, Thornton Hall, Charlottesville, VA 22904 United States
AU: Reisenfeld, D B
EM: dan.reisenfeld@umontana.edu
AF: Los Alamos National Laboratory, Space and Atmospheric Science Group NIS-1, Los Alamos, NM 87545 United States
AU: Reisenfeld, D B
EM: dan.reisenfeld@umontana.edu
AF: University of Montana, Department of Physics and Astronomy, 32 Campus Drive, Missoula, MT 59812 United States
AU: Tokar, R L
EM: rlt@lanl.gov
AF: Los Alamos National Laboratory, Space and Atmospheric Science Group NIS-1, Los Alamos, NM 87545 United States
AU: Sittler, E C
EM: Edward.C.Sittler@nasa.gov
AF: Goddard Space Flight Center, Code 692, Greenbelt, MD 20771 United States
AB: During the Saturn Orbit Insertion on 1 July 2004, the Cassini-Huygens spacecraft flew over Saturn's rings, performing the closest ever encounter with these spectacular features. The CAPS instrument made plasma measurements immediately over the B and A rings, as well as over the Cassini, Encke and Keeler gaps. The electron spectrometer measured electrons between 0.5 and 28,000 eV with 2s time resolution, within a 160 degree fan-shaped field of view directed partly towards the rings in this interval. The Ion Mass Spectrometer measured ions between 1 and 50,000 eV with a similar field of view. During much of this time the spacecraft was in solar occultation, and spacecraft-produced photoelectrons were therefore absent. When the spacecraft left the protection of the main rings and features, penetrating radiation associated with Saturn's radiation belts appeared, confirming that the rings absorb radiation belt particles. The new low energy plasma results over the rings showed: (1) significant enhancements in the fluxes of electrons above the Cassini, Encke and Keeler gaps, (2) spectral signatures of electrons above the A ring which may contain information about ring material, (3) the presence of electrons within the ring ionosphere with changing properties throughout the period and (4) ion signatures consistent with corotation of oxygen. Here we will present the CAPS observations and preliminary interpretations.
DE: 7815 Electrostatic structures
DE: 5737 Magnetospheres (2756)
DE: 6213 Dust
DE: 6275 Saturn
DE: 2756 Planetary magnetospheres (5443, 5737, 6030)
SC: Planetary Sciences [P]
MN: 2004 AGU Fall Meeting