By studying the subtle shifts of aurorae on Ganymede, scientists working with the Hubble Space Telescope have concluded that Jupiter's largest moon hosts a massive subterranean ocean. Quite suddenly, the outer reaches of our solar system appear to be a very wet place, indeed.
NASA scientists says that the largest moon in the solar system may harbor life in its inner oceans. Previously, scientists thought Ganymede only had one ocean between two ice layers, but data reveals that its structure is "ice and oceans stacked up in several layers like a club sandwich."
Here's something you've never seen before: Ganymede, Jupiter's largest moon, caught on video as its orbit takes it behind the gaseous giant. Incredible.