Unformatted text preview: be caused by compositional convection in the core,  if the magnetic field is the product of dynamo action, or magnetoconvection.   Despite the presence of an iron core, Ganymede's magnetosphere remains enigmatic, particularly given that similar bodies lack the feature.  Some research has suggested that, given its relatively small size, the core ought to have sufficiently cooled to the point where fluid motions and a magnetic field would not be sustained. One explanation is that the same orbital resonances proposed to have disrupted the surface also allowed the magnetic field to persist: with Ganymede's eccentricity pumped and tidal heating increased during such resonances, the mantle may have insulated the core, preventing it from cooling.  Another explanation is a remnant magnetization of silicate rocks in the mantle, which is possible if the satellite had a more significant dynamo-generated field in the past....
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- Fall '10
- Astronomy, Magnetic Field, Planet, Magnetic moment, Orbital resonance