... Solar System . ... Planets . ... Saturn is the sixth planet from the Sun and is the second largest in the solar system. A day on Saturn is 10 hours 39 minutes long, and it takes 29.5 Earth years to revolve about the Sun.€аThe atmosphere is primarily composed of hydrogen with small amounts of helium and methane.€аAt the last count it had 62 Moons, but it is another feature of this gas planet which makes it spectacular, its ring system. ... The first man to notice the rings of Saturn was Galileo. ...