Weiss, J.W., Porco, C. C., Richardson, D. C., Dones, L. (2006). "A Near-Arm/Far-Arm Asymmetry in Saturn's Rings and Implications for Ring Structure." American Astronomical Society, DPS meeting #38, #38.04.


Abstract
Low latitude images of Saturn's rings taken with the imaging science (ISS) cameras onboard from the Cassini spacecraft have shown a curious phenomenon: one arm of the rings will often appear brighter than the other. This asymmetry between the near and far arms can be seen in both the A and B rings and appears even in cases where the spacecraft is so far from the planet that the emission angles from the ring arms is virtually identical.
We will present our work using our ray-tracing code which shows that the near arm/far arm asymmetry can be explained by the presence of self-gravity wakes in both rings. We will also demonstrate that the asymmetry implies that the B ring is very thin, less than 10 m FWHM and likely less than 5 m FWHM. We compare our results with recent findings from stellar occultations with Cassini UVIS (Colwell et al., submitted to Icarus and with numerical simulation work.