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Tidal instability as the source for Io's magnetic signature
Author(s) -
Kerswell Richard R.,
Malkus Willem V. R.
Publication year - 1998
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/98gl00237
Subject(s) - tidal heating , jupiter (rocket family) , geophysics , physics , magnetic field , instability , spacecraft , tidal acceleration , tidal force , mantle (geology) , geology , astrophysics , astrobiology , astronomy , planet , mechanics , quantum mechanics
Recent observations from the Galileo spacecraft suggest that Io, the innermost of Jupiter's satellites, has a magnetic signature. Remanent magnetization appears inadequate to explain this signal and, given the huge tidal heating of Io's mantle, a convectively‐stirred molten core seems unlikely. Instead, we propose that Io's magnetic field may be a direct consequence of hydromagnetic instabilities driven in its molten core by Jupiter's tides. Laboratory realisations of such ‘tidal' instabilities confirm their potency as a means for extreme ‘stirring’ and dissipation. The energy to sustain Io's magnetic field would then come ultimately from Jupiter's rotational energy rather than an internal source as currently favoured in the Earth's case.