Page 32 - Curriculum Visions Dynamic Book
P. 32
The rock layers of Ganymede are surrounded by shells of water in ice or liquid form (shown in blue and white).
This closeup colour picture
of the partly cratered surface of Ganymede was
The light regions look like cracked ice. The grooves that crisscross these regions are hundreds of metres deep and hundreds of kilometres long. They may be places where the ice has been cracked apart, perhaps by the churning motion of the ocean below. Any cracks formed in the ice would soon be frozen over.
Ganymede is the only moon known to have a magnetosphere, or region of magnetism. Again, it is likely that it is made by convection currents churning over in a metal/rock core. Ganymede’s and Jupiter’s magnetospheres interact, producing spectacular auroras.
Ganymede’s magnetic field may be partly responsible for the appearance of the polar landscape.
Complex sets of ridges and grooves
in the Nippur Sulcus region on Ganymede. The large crater at the bottom is about 12 kilometres in diametre.
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