Scientists stumped by mysterious cyclones at Jupiter’s poles

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Enormous polygon-shaped cyclone systems at Jupiter’s north and south poles have left scientists baffled over how they maintain their bizarre but beautifully geometric shapes for years.

The hurricane-force storms — each the size of the continental United States — have remained inexplicably stable in their strange configurations since they were first discovered by the Juno spacecraft in 2017.

At the north pole of the Gas Giant, the spacecraft observed a massive cyclone surrounded by eight smaller cyclones that appear to swirl around it. At the south pole, a similar structure of cyclones exists in a hexagonal shape.

Now a group of scientists, led by Andrew P. Ingersoll of the California Institute of Technology, said they may have found some explanation for the strange phenomenon on the planet — the largest in the solar system.

The scientists found that it appears “an anticyclonic ring” between the main cyclone and the smaller cyclones is keeping the clusters in their unique polygonal patterns, according to the new study on the north pole vortices, published Wednesday in Nature Astronomy. 

Scientists have been baffled for years by the polygon-shaped cyclone patterns that form at Jupiter’s poles.
NASA/JPL-Caltech/SwRI/ASI/INAF/JIRAM

Numerous questions about the storms still remain, however.

“Since 2017 the Juno spacecraft has observed a cyclone at the north pole of Jupiter surrounded by eight smaller cyclones arranged in a polygonal pattern,” the study says. “It is not clear why this configuration is so stable or how it is maintained.”

“The polygons and the individual vortices that comprise them have been stable for the 4 years since Juno discovered them,” researchers continued. “The polygonal patterns rotate slowly, or not at all.”

Researchers used a series of images captured by the Juno’s Jovian InfraRed Auroral Mapper [JIRAM] on Juno to track the winds with the polar cyclone and two of the circumpolar ones, according to the study.

However, the scientists did not find what they had expected based on previous “assumptions about the dynamics” regarding “the expected signature of convection—a spatial correlation between divergence and anticyclonic vorticity.”

Additional research on Jupiter’s southern cyclones are needed to reconcile the conflicting data, researchers said.

“These cyclones are new weather phenomena that have not been seen or predicted before,” said Cheng Li, a Juno scientist from the University of California, Berkeley in a 2019 NASA study about the cyclones.

“Nature is revealing new physics regarding fluid motions and how giant planet atmospheres work. We are beginning to grasp it through observations and computer simulations. Future Juno flybys will help us further refine our understanding by revealing how the cyclones evolve over time.”

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