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(2016·太原二模)Washington: NASA has announced evidence that Jupiter's largest moon, Ganymede, has a saltwater ocean under its icy surface. The ocean seems to have more water than all the water on Earth's surface, according to new Hubble observations.
New Hubble observations of Ganymede's magnetic field strongly suggest that the moon, which is the largest in our whole solar system, is home to a subsurface ocean.
Scientists estimate that the oceanis 95 kilometres thick, which is about 10 times deeper than Earth's oceans. But unlike our salty waters, Ganymede's ocean is buried under 150 kilometres of ice.
While scientists have speculated (推测) since the 1970s about the presence of an ocean on Ganymede — the largest moon in our solar system — until now the only observational evidence came from a brief flyby by the Galileo spacecraft, which didn't observe the moon long enough to confirm a liquid ocean.
