Saturn is home to one of the most beautiful and interesting features in the solar system - its dynamic rings. These rings make Saturn the jewel of our celestial neighborhood and have fascinated astronomers, amateur and professional alike, since Galileo first pointed a telescope to the sky. A new image taken by the Cassini spacecraft show that the Saturnian rings still have some surprises for us.
When the rings are imaged in ultraviolet, it becomes very clear that the rings are divided into clumps of particles with gaps between the clumps; instead of a uniform distribution of particles like scientist have always thought. Larry Esposito, the principle investigator of any ultraviolet images Cassini captures, described this from the perspective of a plane, "If you were flying under Saturn's rings in an airplane, you would see these flashes of sunlight come through the gaps, followed by dark and so forth. This is different from flying under a uniform cloud of particles."
Because it looks like Saturn's rings are clumpier than previously suspected, it means that our estimation of its mass could be two to three times smaller than it really is. Josh Colwell from the University of Central Florida (and a member of the Cassini ultraviolet imaging spectrograph analysis team) said, "These results will help us understand the overall question of the age and hence the origin of Saturn's rings."
Because these clumps form so close to Saturn (specifically, inside the Roche limit), they will never form into a moon. The particles exist in a constant ballet of clumping together by their own gravity and being ripped apart by the tidal stresses exerted by Saturn. Even then, Colwell continues to state that the majority of particles in the rings are in one of these clumps (that can form to be 30 to 50 meters [100-160 feet] across) and tend to move clump to clump as the new ones are formed and the old ones are destroyed.
Astronomers will continue to use ultraviolet images from Cassini as well as watching Saturn transit background stars (allowing scientists to watch a star's light dim when sections of the rings pass in front of it) to study the distribution and shape of Saturn's rings.