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Questions About Saturn

Saturn is one of the most identifiable objects in the solar system. Because it's so easily visible in the night sky, we can't say that anyone "discovered" the planet. However, there's probably a lot you don't know about the sixth planet from the sun. Even though probes have been sent to explore Saturn and its moons and rings, there is much more to learn.

Composition and Size
- Unlike Earth, Saturn is not made of solid material--you can never be "on" Saturn. Instead, it's composed mostly of light gases like hydrogen and helium. Saturn is also about 95 times more massive than Earth. It's second only to Jupiter in terms of sheer size. To put it a different way, 765 Earths could fit inside of Saturn. Because the planet is mostly gas, Saturn is significantly less dense than Earth.
Rings
- This image shows the intricate structure of the rings.
  
  All of the outer, gassy planets have ring systems, but Saturn's is the most visible and complicated. Scientists theorize that rings are formed when a moon draws too close to the planet and is ripped apart by gravity. The rings are composed of ice and rock and appear solid from far away, but they are really quite diffuse. Depending on how Saturn is oriented to Earth, we can see the top, bottom or profile view of the rings.
Moons
- Saturn has a wide variety of moons.
  
  The moons that orbit Saturn comprise a solar system in miniature. There are tiny moons which aren't even round, and large moons like Titan which have their own atmosphere. The first of Saturn's moons to be discovered was Titan in 1655. In 2011, scientists know of 53 moons, but this number is sure to grow. As part of the Cassini mission, the Huygens probe was dropped into Titan's atmosphere in 2004--the first time an object has been put on a moon other than Earth's own moon.
Close Encounters
- The Voyage and Pioneer missions broke new ground in Saturn exploration.
  
  In 1979, Pioneer 11 made the first close approach to Saturn on its way out of the solar system. It returned new data about the rings and moons, and the most detailed pictures of the planet anyone had seen. Voyagers 1 and 2 followed several years later, adding to the store of knowledge about Saturn. More recently, the Cassini probe entered orbit of Saturn in 2004 and has been making detailed observations of the system ever since.

Astronomy