Those Remarkable Rings
The hundreds of rings orbiting around Saturn are made up of billions of ice and rock particles, with sizes ranging from small debris to chunks as big as houses. The rings themselves are believed to be pieces of comets, asteroids or shattered moons that broke up before they reached the planet.
Image right: Artist's rendition of Saturn's rings.
Image credit: NASA/JPL
Each ring orbits at a different speed around the planet. Data from the Cassini-Huygens mission will help us understand how they formed, how they maintain their orbit and, above all, why they are there in the first place.
While the other three gaseous planets in the solar system -- Jupiter, Uranus and Neptune -- have rings orbiting around them, Saturn's are by far the largest. With a thickness of only 1 kilometer (0.6 miles) or less, they span up to 282,000 km (175,000 miles), about three quarters of the distance between the Earth and the moon.
Named alphabetically in the order they were discovered, the rings are relatively close to each other, with the exception of the Cassini Division, a gap measuring 4,700 kilometers (2,920 miles). To enter Saturn's orbit, the spacecraft will fly through the gap between the F and the G rings, farther from the planet than the Cassini Division.
Image left: Saturn's rings taken by Voyager 1
As a safety measure, during the crossing of the ring plane, instruments and cameras onboard the spacecraft will be shut off temporarily. However, the spectacular crossing into Saturn's orbit will bring incredible information, images and footage, while the instruments onboard will collect unique data that may answer many questions about the rings' composition.
NASA's Jet Propulsion Laboratory