Bonn 2010 – scientific programme

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EP: Fachverband Extraterrestrische Physik

EP 9: Planets and Small Bodies II

EP 9.6: Talk

Wednesday, March 17, 2010, 10:00–10:15, AKM

Multifrequency Electromagnetic Sounding of the Galilean Satellites' Interiors — •Mario Seufert, Joachim Saur, and Fritz M. Neubauer — Institut für Geophysik, Universität zu Köln

We investigate the temporal variations of the Jovian magnetospheric field at the Galilean satellites' positions and analyze possible inductive responses from the moons' interiors on the basis of classical electromagnetic theory. By using a magnetospheric model that includes contributions of Jupiter's internal field, the current sheet field and fields due to the magnetopause boundary currents, we deduce the corresponding amplitude spectra at each satellite. These spectra provide the strength of inducing signals at different periods for all magnetic components. Short excitation periods (~10 hours) occur due to the fast rotation of Jupiter with respect to the moons' orbital motion. Longer periods (~40 to 400 hours) arise from contributions of the magnetopause field and due to the eccentricity and inclination of the satellites' orbits. Further we analyze various established interior models for all moons and determine answering functions for multiple subsurface conducting layers. We examine the possibility to measure signals of conductive cores in the presence of conductive subsurface liquid water and lava oceans. We also discuss suitable flyby configurations for future missions that could lead to a better understanding of the moons' interiors.