Coupled Orbital and Thermal Evolution of Ganymede
نویسندگان
چکیده
the fact that contraction produced by melting ice I offsets expansion produced by melting high-pressure ice phases. Solid– We explore the hypothesis that passage through an eccentricsolid phase transitions cause negligible satellite expansion. Lithity-pumping resonance could lead to the resurfacing of Ganyospheric stresses caused by expansion of 2% over 10 to 10 mede. To do so, we couple R. Malhotra’s (1991, Icarus 94, years are p10 bars at the surface, and drop to a few bars at 399–412) orbital model for the tidal evolution of the Laplace several kilometers depth. Such stresses could cause cracking resonance to an internal model of Ganymede. Our model exto depths of several kilometers. The cracking and near-surface plores the conditions under which Ganymede can undergo production of warm or partially molten ice make resurfacing global thermal runaway, assuming that the Q/k of Ganymede a plausible outcome of a large thermal runaway. The tidal is strongly dependent on internal temperature. (Here Q is the heating events proposed here may also be relevant for generatidal dissipation function and k is the second-degree Love numtion of Ganymede’s modern-day magnetic field. 1997 Academic ber.) We allow the system to pass through the v1/v 2 P 2 or Press v1/v2 P 1/2 resonance, where v1 ; 2n2 2 n1 , v 2 ; 2n3 2 n2 , and n1 , n2 , and n3 are the mean motions of Io, Europa, and Ganymede. If Ganymede’s initial internal temperature is either
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