Transcript: Saturn, sixth planet out from the Sun, is second only to Jupiter in size and mass. Its atmospheric composition is also similar to the chemical composition of the Sun, 90 percent hydrogen, 5 percent helium, plus methane, ammonia, water vapor, and other gases. The temperature is also similar to Jupiter, and there are winds of three to four hundred miles per hour in the atmospheric bands. Saturn, like Jupiter, has an internal energy source but a much weaker magnetic field than Jupiter. It's less dense than water on average, and Saturn, in addition to its spectacular ring system, has over two dozen moons.