Dyudina, U.A., Ingersoll, A. P., Ewald, S. P., Porco, C. C., Fischer, G., Kurth, W. (2006). "Lightning on Saturn observed by Cassini ISS and RPWS during 2004-2006." American Astronomical Society, DPS meeting #38, #5.02.


Abstract
We report on Cassini Imaging Science Subsystem (ISS) and Radio and Plasma Wave Science (RPWS) observations that indicate lightning on Saturn. Radio emissions (Saturn Electrostatic Discharges, or SEDs) occur when a are bright cloud erupts at 35 degrees South planetocentric latitude. The cloud typically lasts for several weeks, and then both the cloud and the SEDs disappear. They may reappear again after several months. As of July 2006, four such correlated visible and radio storms have been observed since Cassini Saturn Orbit Insertion (June 2004). In all four cases the SEDs are periodic with roughly Saturn's rotation rate, and show correlated phase relative to the times when the clouds are seen on the spacecraft-facing side of the planet. The storm clouds erupt to unusually high altitudes and then slowly descend and spread. The eruption lasts for less than a day during which time the SEDs reach their maximum rates. This suggests vigorous atmospheric updrafts accompanied by strong precipitation and lightning. Unlike ubiquitous thunderstorms on Earth or Jupiter, only one latitude on Saturn has produced exceptionally strong thunderstorms during the two years of Cassini observations.
This research was supported by the NASA Cassini Project