Saturn’s Super Storms, Great White Spots, Get Explained

Researchers have been able to understand how the giant storms of Saturn behave. The astronomers observed data collected by the Cassini space probe, a joint mission by NASA, the European Space Agency and the Italian Space Agency, orbiting Saturn.

Saturn’s giant storms occur once every 30 Earth years, one Saturnian year, and are also referred to as Great White Spots because of their appearance. The last Saturn storm occurred in 2010 and covered a distance of 10,000 kilometers, or 6,213 miles. The researchers, from the Planetary Sciences Group of the University of the Basque Country, used the Cassini data as well as computer models of the storms to discover how they behave, and their research was published in the journal Nature Geoscience.

The 2010 Saturn storm lasted for seven months and first started as a small white cloud but grew quickly over that time period, the press release notes. As the clouds gathered, forming a gigantic ring, the storm soon had a surface area that measured thousands of millions of square kilometers. The researchers started their study of the Saturn storm at its point of origin, or the head of the storm.

The researchers measured wind speeds at the head of the storm. At this point, the storm is approximately 40 kilometers, or 25 miles, above the cloud level of Saturn and is actively interacting with the planet’s atmosphere. According to the news release, the wind speed at the head of the storm could reach speeds of 500 kilometers an hour, or 311 mph.

Higher up in the atmosphere, the storm releases large amounts of water vapor into the upper atmosphere of Saturn. The “focus” of the storm is located 300 kilometers, 185 miles, above the cloud level. As the water vapors travel to the upper regions of the atmosphere, it creates new clouds and releases an enormous quantity of energy, the news release notes. This burst of energy soon interacts with the already high winds in the upper atmosphere of Saturn, which can be as high as 1,800 kilometers per hour, or 1,100 mph, according to NASA, which create the wind storms in the lower part of the atmosphere.

“We did not expect to find such violent circulation in the region of the development of the storm, which is a symptom of the particularly violent interaction between the storm and the planet's atmosphere,” said lead researcher Enrique García Melendo, from the Fundació Observatori Esteve Duran -- Institut de Ciències de l'Espai, of Catalonia. The researchers believe they can use the same computer models to track and study similar meteorological phenomena on Earth.