By Clara Moskowitz
Staff Writer
posted: 22 September 2008
8:00 p.m. ET
Saturn's rings may be much older and more massive than previously thought, according to a new study.
The study's computer simulation showed how the planet's rings could date back billions of years ago to the early ages of the solar system, rather than only 100 million years ago (during Earth's Age of Dinosaurs), as previous observations suggested. The calculations are consistent with recent observations of the rings by the Cassini–Huygens spacecraft currently studying Saturn and its moons.
Larry Esposito and Joshua Elliott, both at the University of Colorado, modeled how meteorites smash into the rings, shattering the ring particles and coating each one in a layer of ice and dust. Before, scientists had assumed that this shattering led to the eventual dissipation of the rings, but a new simulation, created by Glen Stewart and Stuart Robbins of the University of Colorado, shows that after breaking up, the particles could again clump together in a perpetual recycling process.
Previously, researchers had thought the rings were relatively young because they appeared bright and pristine, not covered with the detritus of billions of years of meteorites smashing into them. But the new calculations show that if the effect of this clumping and re-clumping is taken into account, the dust would also be recycled through the rings and wouldn't appear as dark as might be expected.
Many scientists had assumed that we just happened to be catching Saturn at a relatively rare time when it had rings. Now it would seem Saturn, and maybe lots of other large planets in the universe also, could have rings for much of their lives.
more:
http://www.space.com/scienceastronomy/080922-saturns-rings.html