The "Dagwood Sandwich" Moon. Earlier models of Ganymede's oceans were based on the assumption that the existence of salt didn't change the nature of liquid very much with pressure. However, Dr. Vance and his colleagues found, through laboratory experiments, that salt does increase the density of liquids under the extreme conditions hidden deep within Ganymede and similar icy moons with subsurface bodies of water. Imagine adding table salt to a glass of water. Instead of increasing in volume, the liquid will actually shrink and become denser. The reason for this is that salt ions lure water molecules.
Only recently have space missions begun to solve this beguiling Solar System mystery--that a small number of distant moons have been successfully hiding, from the curious eyes of astronomers, life-sustaining liquid water beneath secretive shells of ice.
Saturn is the smaller of the two gas-giant planets, twirling around our Sun, in the outer regions of our Solar System--far from the delightful warmth of our lovely incandescent roiling gas-ball of a Star. Jupiter is the larger of the duo of gas-giants dwelling in our Solar System, as well as the largest planet in our Sun's bewitching family, which is composed of eight major planets, an assortment of moons and moonlets, and a rich menagerie of smaller objects. Saturn is the second-largest planet in our Solar System--and probably the most beautiful.