Where would you go to find the largest known lightning storms?

The largest and most powerful lightning storms known are not on Earth, but in the atmosphere of Saturn. Starting in late January, the Radio and Plasma Wave Science Instrument on the Cassini spacecraft orbiting Saturn began picking up huge bursts of static, similar to what AM radios experience on Earth during thunderstorms. These bursts were traced to a storm in Saturn's southern hemisphere. This storm is about the size of the continental United States. Based on the strength of the radio signals, the lightning flashes are estimated to be 1000 times stronger than any lightning on Earth. As of mid-February, the storm was continuing.

The storm itself was large enough to be seen with amateur telescopes. See http://www.nasa.gov/vision/universe/solarsystem/Saturn_storm.html for some photos.

For more about this storm, see the news release http://www.uiowa.edu/~ournews/2006/february/021406saturn_lightning.html

An audio file of the static from the storm can be found at
http://www-pw.physics.uiowa.edu/space-audio/cassini/cas-sed-06-023-2hr/

More information about the ongoing Cassini-Huygens mission can be found at http://saturn.jpl.nasa.gov/home/index.cfm

This week's question comes from Dr. Dave Thompson. Dr. Thompson is an astrophysicist who studies gamma rays in the Exploration of the Universe Division. He helped build, test, and analyze data from EGRET on the Compton Gamma Ray Observatory, and he is now helping build part of the Gamma Ray Large Area Space Telescope (GLAST), scheduled for launch in 2007. His particular scientific interest is gamma-ray pulsars.