o small-scale features, giving the impression of waves and eddies. The wind velocity at the cloud tops seems to be about 1,400 kilometers per hour, or twice that of Jupiter.According to a recent theory, Saturn has an iron and rock core that extends out 13,000 to 14,000 kilometers from its center and is so compressed that it contains 15 to 20 times the mass of the Earth. Surrounding the core is a layer of electrically conductive metallic hydrogen in liquid form, outside of which is an envelope of hydrogen and helium. There is a magnetic field 1,000 times stronger than that of the Earth, though far weaker than that of Jupiter. The magnetic axis is almost coincident with the axis of rotation, and the magnetosphere extends out beyond the orbit of the largest satellite, Titan. There are fairly strong radiation belts, but these, again, are much weaker than those of Jupiter.The temperature at the cloud tops of Saturn is approximately –180 C. A theory that the planet might be self-luminous has been disproved. Saturn, like Jupiter, releases about twice the amount of energy it receives from the Sun, indicating the existence of an internal source of heat. While Jupiter emits energy from the gravitational contraction that occurred when the planet was formed about 4,600,000,000 years ago, it is unlikely that the heat source of Saturn is similar. Saturn is smaller and less massive and has a lower overall density, therefore, any heat remaining from the gravitational contraction of Saturn would have been dissipated long ago. Instead, the heat source of Saturn may result from the separation of hydrogen and helium in the planet’s outer layers, with the heavier helium sinking through the liquid hydrogen middle layer.The rings of Saturn are much more prominent than those of Jupiter or Uranus, and they are different in nature. Saturn’s rings are made up of icy or ice-covered particles. Each ring moving around Saturn moves in its own indep...
