Posted: Thu, Jul 8, 2004, 7:56 AM ET (1156 GMT)
Spectroscopic data from NASA's Cassini spacecraft has shown that the composition of Saturn's extensive ring system is not uniform but varies from region to region. Scientists at the University of Colorado reported Wednesday that while water ice is the dominant constituent in the rings, the amount of water varies, increasing in the outer rings. Cassini has also detected possible silicate and organic materials in the ring that one scientist described as "mud". The results support models that use the breakup of a large icy object to explain the formation of the planet's rings.
