Scientists think that the interaction of water and rock could possibly support life; in the previous model, it was assumed ice coated the moon's rock bottom. But no longer. "This is good news for Ganymede," Vance said. "Its ocean is huge, with enormous pressures, so it was thought that dense ice had to form at the bottom of the ocean. When we added salts to our models, we came up with liquids dense enough to sink to the sea floor."