Saturn's rings are made up mostly of water ice with a light coating of other material, most probably dust from comets and asteroids that may have gotten too close to Saturn and were broken apart. Saturn has the largest ring system of any planet in our solar system. Galileo first saw Saturn's rings through his telescope in 1610. He thought he was seeing two large moons, one on each side of Saturn. Scientists finally figured out that what Galileo saw wasn't moons but rings instead.
Tiny moons play a large role in keeping the rings in place.
I work at the Jet Propulsion Laboratory in Pasadena. We fly the Cassini spacecraft by sending up commands to a large computer on board. We send up enough commands to fly Cassini for about 2 months. Sometimes we send up a few extra commands during that month if we decide to do something that we hadn't planned to do originally. As a CIRS team member I help plan the commands that CIRS will need for the next few months.