Wednesday, October 7, 2009
The Phoebe Ring
Yesterday, scientists Anne J. Verbiscer and Michael F. Skrutskie of the University of Virginia and Douglas P. Hamilton of the University of Maryland announced a new ring found around Saturn, currently known as the Phoebe Ring. It's virtually invisible at visible wavelengths, and was discovered with the Spitzer infrared space telescope. It extends from 128 to 218 Saturn radii; this just touches Phoebe's orbit at 207 radii. The ring is thought to have come from micrometeorite impacts on Phoebe. It may also be responsible for the two-tone coloration of Iapetus. Interestingly, the idea of the ring was proposed by Joseph Burns, who also proposed it as a mechanism for Iapetus's coloring.