Gigantic Storm on Saturn Explained: Extreme Space Weather

Massive storms swirl around Saturn, creating extreme weather that makes the planet hostile to life. Now, though, scientists have found the reason behind these gigantic storms. The findings could reveal further insight into weather on other planets, which is crucial to understand for future space missions.

About once every Saturnian year, the equivalent of 30 Earth years, an enormous storm is created on the ringed planet. This affects the atmosphere on a global scale, creating a situation where storms can sometimes wrap around the entire planet. Known as Great White Spots, these massive storms were first seen in 1876. It's only now, though, that scientists have gotten a high resolution image from the Cassini space vehicle of one of these storms.

This particular storm started in 2010 and is the sixth one to be observed thus far. It first started as a small, brilliantly white cloud in the middle latitudes of the northern hemisphere of the planet. Then, the cloud started to grow. It burst outward, expanding to form a cloudy and turbulent ring with a surface area of thousands of millions of square kilometers. It churned and remained active for more than seven months.

In order to learn a little bit more about what may have caused this storm and others on Saturn, the researchers took a closer look at the images. More specifically, they focused on where the storm originated, known as the "head" of the storm. These intense winds howled around the planet's atmosphere at a phenomenal 500 kilometers per hour.

"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 Enrique Garcia, one of the researchers, in a news release.

Yet how did this violent storm form in the first place? The researchers designed mathematical models that could reproduce the storm on a computer. This allowed them to examine the physical explanation for the storm's behavior--especially its lengthy duration.

It turns out that the focus of the storm is located about 186 miles above visible clouds and that the storm itself transports enormous quantities of moist gas in the form of water vapor to the highest levels of the planet. This forms visible clouds and liberates enormous quantities of energy. The energy then reacts violently with the dominant wind of Saturn to produce the massive storms.

Despite the enormous activity of the storm, though, its violence was still not enough to modify the prevailing winds. These winds blow permanently in the same direction--rather like Earth's parallels. This means that while these storms can be huge, they're still not big enough to completely change the winds of Saturn.

The findings have showed researchers a little bit more about the underlying reasons for storm formation. The research could also be applied to Earth's own atmosphere; the models that were used could be reworked to apply to our own planet.

The findings are published in the journal Nature Geoscience.