The Cassini Spacecraft has spotted an enormous storm on the planet Saturn, taking up a good chunk of the planet’s northern hemisphere (see picture). It was 10,000 kilometres across and 10,000 times stronger than anything seen here on Earth. In fact, it was so powerful that the energy tied up in the storm was equal to the entire amount of energy Saturn receives from the sun.
Given the fact that Saturn is about 1.5 billion kilometres from the sun (about 10 times the distance of the earth), it may seem surprising that any thunderstorms can form at all. Well at the atmospheric pressure of earth you’d be right—it’s just too cold for thunderstorms to form. But 200 kilometres further down, heat radiating from the planet’s centre is strong enough to allow for the formation of weather events.
In fact, the Voyager 1 spacecraft, now on its way out of the solar system, first detected lightning on Saturn back in 1980. What makes this storm different is that it so big. The researchers involved think that it may be tied to Saturnian springtime, which is just coming to the northern hemisphere.
Image courtesy Carolyn Porco and CICLOPS; credit NASA/JPL-Caltech/SSI