In 1664, jack-of-all-trades astronomer Giovanni Domenico Cassini set his telescope’s lens on Jupiter and observed the bands and spots of the planet. Later, in 1675, he discovered a narrow gap separating Saturn’s rings into two parts. The gap was later named the Cassini Division. His discoveries were monumental, but added more mystery to the celestial bodies above.

“Since the pioneering telescope observations of (Cassini) in the mid-17th century, stargazers have wondered about the bands and spots of Jupiter,” said Prof. Moritz Heimpel, who teaches physics at the Univ. of Alberta. “The average citizen can now pick up a backyard telescope and see the structures that we write about today. However, even in the present age with the Cassini spacecraft orbiting Saturn and the Juno craft approaching Jupiter, there is considerable debate about the dynamics of the atmosphere of the giant planets.”

With 3-D modeling from supercomputers and fluid dynamic equations, Heimpel and colleagues have simulated jet streams—the aforementioned bands—and storms—the aforementioned spots—of the two planets that caught Cassini’s explorative eyes.

The study was published in Nature Geoscience.

With Jupiter and Saturn, one huge question is just how deep the weather structures penetrate into the gas giants. “There’s no solid surface to stop them,” Heimpel said. “Our simulations imply that the jet streams plunge deep into the interior, while the storms are rather shallow.”

According to the researchers, storms on the planets can persist for centuries. Jupiter’s famous Great Red Spot, a giant anti-cyclonic storm, has been present for over 300 years of human observation.    

The team’s research will gain new footing, as the Cassini and Juno spacecrafts move into polar orbits of their respective planets—Juno in summer 2016 and Cassini in 2017. Heimpel said the two missions will be imperative to verifying predictions from their computer simulations. “More importantly, the missions will lead to new questions and controversies that we will address with even more sophisticated analysis,” he said.

As with scientific discoveries from years past, new discoveries will open the doors to new mysteries.