Saturn Facts



  • Saturn is the second biggest planet in the Solar System – 815 times as big in volume as the Earth, and measuring 120,000 km around its equator.
  • Saturn takes 29 and a half years to travel round the Sun, so Saturn’s year is 29.46 Earth years. The planet’s complete orbit is a journey of more than 4.5 billion km.
  • Winds ten times stronger than a hurricane on Earth swirl around Saturn’s equator, reaching up to 1,100 km/h – and they never let up, even for a moment.
  • Saturn is named after Saturnus, the Ancient Roman god of seed-time and harvest. He was celebrated in the Roman’s wild, Christmas-time festival of Saturnalia.
  • Saturn is not solid, but is made almost entirely of gas – mostly liquid hydrogen and helium. Only in the planet’s very small core is there any solid rock.
  • Because Saturn is so massive, the pressure at its heart is enough to turn hydrogen solid. That is why there is a layer of metallic hydrogen around the planet’s inner core of rock.
  • Saturn is one of the fastest spinning of all the planets. Despite its size, it rotates in just 11.5 hours – which means it turns round at over 10,000 km/h.
  • Saturn’s surface appears to be almost completely smooth, though Voyager 1 and 2 did photograph a few small, swirling storms when they flew past.
  • Saturn has a very powerful magnetic field (see magnetism) and sends out strong radio signals. Saturn’s rings are made of many millions of tiny, ice-coated rock fragments Saturn is almost as big as Jupiter.
  • Saturn’s rings are sets of thin rings of ice, dust and tiny rocks, which orbit the planet around its equator.
  • The rings shimmer as their ice is caught by sunlight.
  • The rings may be fragments of a moon that was torn apart by Saturn’s gravity before it formed properly.
  • Galileo was first to see Saturn’s rings, in 1610. But it was Dutch scientist Christian Huygens (1629-95) who first realized they were rings, in 1659.
  • There are two main sets of rings – the A and the B rings.
  • The A and B rings are separated by a gap called the Cassini division, after Italian astronomer Jean Cassini (1625-1712), who spotted it in 1675.
  • A third large ring called the C or crepe ring was spotted closer to the planet in 1850.
  • In the 1980s, space probes revealed many other rings and 10,000 or more ringlets, some just 10 m wide.
  • The rings are (in order out from the planet) D, C, B, Cassini division, A, F, G and E. The A ring has its own gap called the Encke division.