Post link 14 March 2015, 3:58
By Eric Hand 12 March 2015 3:15 pm

The solar system’s largest moon, Ganymede, in orbit around Jupiter, harbors an underground ocean containing more water than all the oceans on Earth. Scientists were already fairly confident in the ocean’s existence, based on the moon’s smooth icy surface—evidence of past resurfacing by the ocean—and other observations by the Galileo spacecraft, which made a handful of flybys in the 1990s. But new observations by the Hubble Space Telescope, published online today in the Journal of Geophysical Research: Space Physics, remove any remaining doubt.

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