The ring particles are held in place by the gravitational interactions of each other and the small satellites embedded in the ring. These “shepherd satellites” ride on the ring particles. Although scientists have always known that Saturn has rings, they don’t know how long the rings exist and when they form. There are two main theories. For years, scientists have believed that this planet and its rings appeared early in the history of the solar system. They believe that the ring is made of existing materials: dust particles, rock asteroids, comets and huge boulders. The theory dominated until the first spacecraft exploration of the Voyager mission, which began in 1981. Images and data show changes in the ring, even in a short period of time. The Cassini mission provides additional information that scientists are still analyzing, indicating that ring particles are lost in a short period of time. Another clue about the age of the ring comes from the very pure water ice of the particles. Scientists believe that this means the ring is younger than Saturn. Over time, older ice particles will be blackened by dust. If this is true, then the ring we see now may not be traced back to the origin of Saturn. Or, due to the gravitational pull of Saturn, the current ring system may have been created when the Mimas-sized moon was too close to and separated from Saturn about 200 million years ago. The resulting debris will then fall into the orbit around Saturn, forming the ring we see today. This lunar split scene is likely to have played many times in the planet’s 4.5 billion year life cycle. According to this theory, the ring we see today is just the latest ring. It is also possible that a very early “Titan” world may participate in the creation of the ring, forming a larger, larger system than is now seen.