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Saturn is the second largest planet in the solar system, with a mass that is 30% of Jupiter's. The smaller size and greater distance from the Sun of 9.5AU mean that Saturn is a colder planet than Jupiter, with a smaller internal energy production.

As Jupiter, Saturn is a giant gaseous planet, with a composition that is primarily hydrogen and helium. Because Saturn is cooler and generating less heat than Jupiter, its atmosphere is less dynamic and its magnetic field is weaker than Jupiter's.

Beyond size and distance, the one feature that sets Saturn apart from Jupiter is the system of rings. Three of the giant planets have rings, but Saturn's are big and obvious, while the rings of Jupiter and Uranus are slight and difficult to see. The rings of Saturn are composed of chunks of ice and rock. The inner radius of the full ring system is 1.14 times Saturn's equatorial radius, and the outer radius is 3.53 times the equatorial radius. Gaps in the rings subdivide them into several parts.

Pastel of Saturn.

While the mass in the rings is small, it is enough to cast a deep shadow on Saturn that influences Saturn's weather. This shadow creates a temperature gradient in the planet's atmosphere that drives thunderstorms. The severity of the effect depends on the orientation of the rings relative to the sun. When the rings are in the plane of Saturn's orbit, the strong shadow drives continuous thunderstorms, while when the rings have a high inclination to the sun, the shadow is mild, and the thunderstorms are sporadic.

Like Jupiter, Saturn has many moons. One of these moons, Titan, is of particular interest, because it is about the same size as Jupiter's Ganymede, but unlike Ganymede, it has a dense atmosphere of nitrogen with clouds of methane and other hydrocarbons. Besides having the second largest moon of the Solar System, Saturn boasts four moons with diameters greater than 1,000 km. The remaining moons are small, but some of these still influence the dynamics of Saturn's rings.

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