HR: 09:30h
AN: P51E-07    [Abstracts]
TI: Observations of Europa's Tenuous Atmosphere
AU: * McGrath, M A
EM: melissa.a.mcgrath@nasa.gov
AF: NASA Marshall Space Flight Center, VP01, MSFC, Huntsville, AL 35824, United States
AU: Hansen, C J
EM: candice.j.hansen@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Dr., Pasadena, CA 91109, United States
AU: Hendrix, A
EM: amanda.hendrix@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Dr., Pasadena, CA 91109, United States
AU: Retherford, K
EM: kretherford@swri.edu
AF: Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78228-0510, United States
AB: Europa is one of numerous planetary satellites now known to possess tenuous atmospheres. Europa's is derived via sputtering of its icy surface by the magnetospheric plasma within which it orbits. Understanding of this tenuous atmosphere is of interest because its composition is potentially diagnostic of its subsurface ocean. Two chapters in the upcoming University of Arizona "Europa" book will provide a detailed review of both the observational foundation for, and the theoretical and modeling efforts to explain, the tenuous atmosphere of this enigmatic satellite. This paper will review the existing observational data, including observations from the Galileo and Cassini spacecrafts, and from the Hubble Space Telescope, which demonstrate that Europa's atmosphere is composed primarily of molecular oxygen that emits via electron dissociative excitation, and sustains a relatively dense ionosphere.
DE: 5405 Atmospheres (0343, 1060)
DE: 5408 Aurorae and airglow
DE: 5410 Composition (1060, 3672)
DE: 5435 Ionospheres (2459)
SC: Planetary Sciences [P]
MN: 2007 Fall Meeting