Saturn

Rock and Gas

Deep inside Saturn there is probably a rocky core. It probably takes up less than 1% of the space inside, but contians as much as a quarter of the planet's mass. The rest of the planet is an enormous ball of gas; mostly hydrogen. The surface clouds that we see are made up of tiny particles of ice like stratus clouds on Earth, but the ice is frozen ammonia instead of water. The winds that rip through this atmosphere are the fastest known: 1800 kilometers per hour!

Rings

The fabulous rings are made up of particles of ice from microscopic snowflakes to house-sized icebergs. The bits of ice and some dust all orbit Saturn together like countless tiny moons, always colliding, mixing, and forming clumps that soon break up. The main rings stretch over 270,000 kilometers across, but may be a mere 10 meters thick! Most of the rings are named with letters from A to G in order of their discovery.

Moons

There are 62 identified moons orbiting Saturn. The named moons range in size from tiny Aegaeon at half a kilometer in diameter, to giant Titan, which is even bigger that the planet Mercury! They range in distance from Pan, which orbits inside the A Ring, to Fornjot, 24.5 million kilometers away, which feels so little gravity that it takes almost four years to creep around its orbit one time! Some of the larger moons are among the most mysterious in the solar system: Enceladus, even at -200 °C, has geysers shooting out of the south pole. Titan's surface is shrouded by clouds floating in an atmosphere even thicker than Earth's, but we know that liquid methane rains on the surface and flows into lakes. Iapetus has a tall mountain range that follows its equator all the way around and hasn't been explained.

Since 2004, the Cassini spacecraft has been orbiting Saturn. Much of what we know, and all the best images come from that mission: