“We feel confident that the sky is not falling”—quite literally. So says Philip Marcus, a professor of fluid mechanics at the University of California, Berkeley. He’s part of a team that looked into the potential fate of Jupiter’s Great Red Spot and determined it’s not at death’s door. NBC News reports photos from May and June showed red “flakes” peeling off the storm; that—combined with century-old data suggesting the Great Red Spot at one time could have fit four Earths inside it and can now hold only a little more than one—caused alarm.
In research presented Monday at the 72nd annual meeting of the American Physical Society’s Division of Fluid Dynamics, the team found the recent flaking could be explained by “a coincidence of two phenomena,” as the New York Times puts it.
The Great Red Spot is an anticyclone, meaning unlike the cyclones we know, it turns counterclockwise. Its vortex sits far below the visible clouds, and “you can’t just conclude that if a cloud is getting smaller that the underlying vortex is getting smaller,” says Marcus. Cyclones occasionally make their way toward the Great Red Spot, and when their winds meet they repel each other.
Anticyclones make their way toward it, too, and the two are attracted to each other. But they aren’t immediately absorbed. CNN uses the metaphor of a snake eating its prey: The Great Red Spot doesn’t “digest” an anticyclone right away. Rather, the smaller one first appears like a lump on the perimeter. Marcus believes the flaking was produced by an anticyclone lump getting shaved off by a cyclone’s winds. Marcus’ prediction? The Great Red Spot will be around for centuries, at least.