This is a movie from the Cassini imaging team showing gigantic lightning flashes inside a storm cloud on Saturn!
Depicting a 16-minute span of time, the movie shows lightning illuminating large, 300-km-diameter areas within the 3,000-km-long cloud. (The “zap zap” sounds were added later to represent the radio signals that were received by Cassini during the flashes. The signals themselves would have been inaudible to our ears but “zap” sure is more fun.)
This movie is a combination of nine images taken in visible light by Cassini’s narrow-angle camera on November 30, 2009 from a distance of 1.6 million miles from Saturn.
Getting pictures of Saturn’s lightning has been tricky because of the brightness of the planet – even on the night side, sunlight reflecting off the rings is brighter than a full moon sky on Earth! It wasn’t until Saturn’s spring equinox in August 2009 when only the edge of the rings was illuminated by the sun was Cassini first able to capture visible light images of lightning.
These new images are significant because it’s the first time researchers have gotten radio data along with the lightning flashes.
“Now that the radio and visible light data line up, we know for sure we are seeing powerful lightning storms.”
– Georg Fischer, Space Research Institute, Graz, Austria
Image credit: NASA/JPL/SSI/University of Iowa