The famous mega-storm on Jupiter turns out to be as flat as an atmospheric pancake

With a width of around 16,000 kilometers, it is large enough to swallow dirt in one bite. The wind is blowing at 430 kilometers per hour, twice as strong as the strongest hurricane to ever wreak havoc on Earth. And oh yeah, it’s probably been raging for at least three and a half centuries. The Great Red Spot, the eye-catching part of the gas giant Jupiter, is arguably the biggest storm in the solar system.

That alone also makes it scientifically interesting. So it’s no surprise that the unmanned research probe Juno, orbiting the gas giant since 2016, subjected the mega-storm to detailed analysis. In the specialist journal Science Two articles were published Thursday evening summarizing the results. With the most striking result: the mega storm is quite flat.

Not that he’s thin as paper. The storm is blowing about 200 to 500 kilometers into Jupiter’s atmosphere, the researchers calculated. But compared to its width, it is remarkably little. This means that the stain is relatively much finer than land hurricanes, roughly comparable to a homemade pancake.

Nevertheless, the storm influences its environment much deeper into the atmosphere. Air currents swirling near the storm are up to 3,000 kilometers deep, research has already shown.

Gravity

According to astronomer Ignas Snellen of the University of Leiden, therefore, it’s not so much the calculated thickness, but how the researchers determined what catches the eye. “I like the way they handled this,” he says. The researchers calculated the thickness of the storm using the gravity exerted by Jupiter on the Juno probe.

To determine the orbits of probes around planets, scientists normally consider a planet as a whole: a kind of solid sphere without variations. The heavier the planet, the more it pulls on the probe with its gravity. In practice, however, this tensile force varies with the distribution of mass under the probe. And this variation is reflected in the speed changes of the ship itself. “They were able to measure this with such precision at Juno that they were able to deduce the thickness of the storm from the change in speed of the probe,” says Snellen. “It’s impressive.”

distant worlds

In a second article researchers describe the structure of multiple vortices in Jupiter’s atmosphere, including the Great Red Spot. This allowed them to determine, among other things, the distribution of carbon and oxygen in Jupiter’s atmosphere. Normally, this is difficult because the oxygen atoms – part of the water molecules – are hidden relatively deep in Jupiter’s atmosphere. Thanks to the vortices that plunge under the cloud layer with water vapor, they still become visible.

“I mainly do research on exoplanets, planets that revolve around stars other than the sun,” Snellen explains. “The oxygen / carbon ratio is a measure of how far a planet is born from a young star,” he says. “If we know this better about Jupiter, then our knowledge of the much more distant worlds will improve as well.”