Saturn

Saturn's interior is similar to Jupiter's consisting of a rocky core, a liquid metallic hydrogen layer and a molecular hydrogen layer. Traces of various ices are also present. Saturn's interior is hot K at the core and Saturn radiates more energy into space than it receives from the Sun. Most of the extra energy is generated by the Kelvin Helmholtz mechanism as in Jupiter.

But this may not be sufficient to explain Saturn's luminosity; some additional mechanism may be at work, perhaps the "raining out" of helium deep in Saturn's interior. The bands so prominent on Jupiter are much fainter on Saturn. They are also much wider near the equator. Details in the cloud tops are invisible from Earth so it was not until the Voyager encounters that any detail of Saturn's atmospheric circulation could be studied.

Saturn also exhibits long lived ovals red spot at center of image at right and other features common on Jupiter. In , HST observed an enormous white cloud near Saturn's equator which was not present during the Voyager encounters; in another, smaller storm was observed left.Two prominent rings A and B and one faint ring C can be seen from the Earth. The gap between the A and B rings is known as the Cassini division.

The much fainter gap in the outer part of the A ring is known as the Encke Division but this is somewhat of a misnomer since it was very likely never seen by Encke. The Voyager pictures show four additional faint rings. Saturn's rings, unlike the rings of the other planets, are very bright albedo. Though they look continuous from the Earth, the rings are actually composed of innumerable small particles each in an independent orbit. They range in size from a centimeter or so to several meters. A few kilometer-sized objects are also likely.

Saturn's rings are extraordinarily thin: though they're km or more in diameter they're less than one kilometer thick. Despite their impressive appearance, there's really very little material in the rings if the rings were compressed into a single body it would be no more than km across.