HR: 11:55h
AN: P11C-07 INVITED     [PDF]
TI: Field and Plasma Science with the Jupiter Icy Moons Orbiter (JIMO)
AU: * Khurana, K K
EM: kkhurana@igpp.ucla.edu
AF: Institute of Geophysics and Planetary Physics, UCLA, Los Angeles, CA 90095 United States
AU: Kurth, W S
EM: william-kurth@uiowa.edu
AF: Dept Physics & Astronomy, Univ Iowa, Iowa, IA 52242 United States
AU: Cooper, J F
AF: NASA Goddard SFC, GSFC, Greenbelt, MD 20771 United States
AU: Waite, J H
AF: Univ Michigan, Space Research Bldg 2455 Hayward, Ann Arbor, MI 48109 United States
AU: Connerney, J E
AF: NASA Goddard SFC, GSFC, Greenbelt, MD 20771 United States
AU: Green, J L
AF: NASA Goddard SFC, GSFC, Greenbelt, MD 20771 United States
AU: Crary, F
AF: Southwest Research Institute, 6220 Culbera Dr., San Antonio, TX 78238 United States
AU: Paterson, W R
AF: Dept Physics & Astronomy, Univ Iowa, Iowa, IA 52242 United States
AU: Johnson, R E
AF: Engineering Physics, Univ. Virginia, Thornton Hall Room B103, Charlottesville, VA 22904 United States
AU: Paranicas, C
AF: Applied Physics Lab, 11100 Johns Hopkins Rd, Laurel, MD 20723 United States
AU: Mauk, B H
AF: Applied Physics Lab, 11100 Johns Hopkins Rd, Laurel, MD 20723 United States
AB: The field and plasma investigations from JIMO would address fundamental science objectives related to chemistry, internal structure and evolution of Jupiter's Galilean icy satellites. In addition, data collected during the cruise phases of the mission would identify azimuthal asymmetries in the structure and dynamics of the Jovian magnetosphere. The Priority 1 objectives identified by the field and plasma subgroup assisting the JIMO SDT are: (1a) determine the presence and distribution of subsurface liquid water in the icy Galilean moons, (1b) determine the nature of satellite-magnetosphere interactions including the radiation environment of these moons, and (1c) determine the surface composition and properties of materials on these moons. The key investigations that reveal the presence and distribution of subsurface liquid water are low-frequency sub-surface sounding and the magnetic induction response of conducting oceans to the changing magnetic field in the rest frames of the moons. The magnetic field is also perturbed by the interaction of the moon with the Jovian plasma. Plasma observations and/or DC electric field measurements are therefore required to separate the internal and external sources of magnetic field perturbations. Further information on the thicknesses and properties of the moon ice crusts, and on the changing magnetic environments of the moons related to the induced fields, would be provided by a low frequency sub-surface sounder (working at kHz to MHz as compared to GHz used by ice penetrating radar). The surface composition objective can be addressed from in situ measurements of neutral or charged species in the moon atmospheres, ionospheres, dust clouds, and orbital gas tori, and by spectrographic imaging of neutral atoms and x-rays from the irradiated surfaces. The Priority 2 objectives are (2a) understanding the asymmetries in the structure and dynamics of Jovian Magnetosphere and (2b) understanding the deep internal structure of the icy Galilean moons. In the cruise phases of the mission, data collected from all local times at near-constant radial distance would help us determine local time asymmetries of the magnetosphere with an unprecedented accuracy. The internal structure objective can be addressed by inferring the magnetic induction response of the cores of the moons at very low frequencies. Electric field, plasma, energetic particle, and radio sounding measurements would further constrain the induction response. Since studies of Io are not a stated goal of JIMO mission, investigations of Io and its torus were assigned to Priority 3. Monitoring of the Io torus with ultraviolet auroral imaging and decametric radio emissions, and of Io's volcanism through imaging, would provide information about one of the principal sources of plasma and dynamics in the Jovian magnetosphere. We will also discuss how, in a conceivable extended phase of the mission, in-situ measurements near Io would shed light on the internal state and structure of this highly active moon and its interaction with the magnetospheric plasma.
DE: 5719 Interactions with particles and fields
DE: 5737 Magnetospheres (2756)
DE: 6218 Jovian satellites
SC: Planetary Sciences [P]
MN: 2003 Fall Meeting