Saturn by order of mass, size, and heliocentric distance is, after Jupiter, the second among the solar system’s giant planets. Its mean distance to the Sun is 9.5 AU. Its diameter is 120,530 km or 9.45 times the Earth’s diameter and its mass amounts to 95 terrestrial masses. Its density is 0.69 g/cm3 such that Saturn is the lightest solar system planet. Saturn is best known for its extensive ring system, much larger and more massive than the ones of the other giant planets. Its atmosphere shows a strong dynamical activity and its magnetosphere, perturbed by the ring system, is unique in the solar system.
Saturn as a Giant Planet
Jupiter and Saturn have the same basic chemical composition, dominated by protosolar gas (mostly hydrogen and helium) which accreted on their rock/ice core at the time of their formation; they are called the gas giants. The difference in density between Jupiter (1.3 g/cm3) and Saturn can be explained by Jupiter being more than three times...