s that are dust-sized up to large mountain-sized masses, with the average size being in the marble to basketball range - about 10 centimeters (four inches). These particles are extremely cold and are possibly composed of frozen water and other ices. An extensive cloud of hydrogen was also discovered around the rings. The rings might have resulted when a moon or a passing body ventured too close to Saturn. The unlucky object would have been torn apart by great tidal forces on its surface and in its interior. In addition, the object may not have been fully formed to begin with and disintegrated under the influence of Saturns gravity. A third possibility is that the object was shattered by collisions with larger objects orbiting the planet (Pioneer 10, 11).Voyager I provided much more detail on the beauty, complexity, and sometimes baffling nature of the rings. The six known rings are actually composed of hundreds of tiny, thin ringlets with intervening spaces, so that the whole ring system looks something like the grooves in a phonograph record. Even the Cassini division, once thought to be empty space between the A and B rings, contains several dozen ringlets. There are far too many rings to be explained by the present theories of how planetary rings form and remain stable. The thin outer F-ring, discovered by Pioneer 11, was resolved into three distinct but intertwined ringlets. This braided ring structure is very difficult to explain; it seems likely that both electrical and gravitational forces are at work. This voyage also helped to discovered that two of Saturns small moons, one on each side of the F-ring, may act as shepherds, their gravitational attraction keeping the ring particles on track between the orbits of the moon (Yenne 126). The first spacecraft flyby accomplished by Pioneer 11 in 1979 accomplished many findings of Saturns composition. The planet has an internal heat source like Jupiter and radiates about ...
