Music My name is Brigette Hesman, and I’m a planetary scientist at NASA’s Goddard Space Flight Center and I study storms on Saturn. A Great White Spot is a massive storm system that erupts on Saturn about once every Saturn year. The Great White Spot that erupted in December, 2010 first presented itself as this fluffy white storm cloud that popped up in the northern hemisphere. The storm when it erupted sent large waves up into the stratosphere and we saw effects like an increased amount of ethylene, something we never expected to see.
In the coming days, the winds on Saturn sheared the storm in both directions and it wrapped all the way across the planet. If you were to scale that to a storm system here on the Earth, what you would have is a storm system that covers all of North America but wraps around the entire planet. There would be no escaping this storm system and it would be lasting for a very long time. This Great White Spot happened to occur ten years before we expected it, which was very fortunate because we happened to have a spacecraft called Cassini in orbit around Saturn,.
And that spacecraft has a full suite of instrumentation that allows us to study this over all wavelength ranges. Some of the effects that we got to see in the infrared were these two bright beacons that started to shine right after the storm erupted in December. Those beacons at first showed temperature differences of about 20 Kelvin, which is reasonable for a storm. However, as time progressed we started to see even larger temperature changes. By May 2011 the two beacons had merged into one, and we saw a temperature change of over 80 Kelvin from the quiet conditions before the storm.