Harvard Researchers’ 3D Simulation May Help Explain Saturn’s Hexagonal Storm

Two Harvard researchers developed a 3D simulation that may help explain the hexagonal pattern of a large storm observed on Saturn.

Researcher Rakesh K. Yadav and Geophysics professor Jeremy Bloxham published the study, titled “Deep rotating convection generates the polar hexagon on Saturn,” in the journal Proceedings of the National Academy of Sciences in June. They were the first to produce a simulation that closely resembles many aspects of Saturn’s distinctive hexagonal storm pattern.

Yadav and Bloxham interpreted the simulation results as evidence that the hexagonal storm may stretch thousands of kilometers deep into the gas planet, rather than being part of a shallow layer of atmosphere.

“The hexagonal flow pattern on Saturn is a striking example of turbulent self-organization,” the researchers wrote in the article. “Here, we argue that the hexagon is likely very deep.”

The pair’s simulation displayed multiple important features that resembled Saturn’s storm pattern: the location of the storm at the planet’s north pole, the storm’s non-circular shape, and the storm winds’ direction.

“I wasn’t expecting it to produce several observations in one fell swoop,” Yadav said. “This computer simulation ended up describing a bunch of things.”

Instead of trying to reason their findings with complex mathematics, Yadav and Bloxham adopted the “numerical simulation approach.” They used physics principles to simulate the basics, then ran their calculations through supercomputers.

“A lot of people try to understand it mathematically using something called the analytical approach. You try to use some mathematical wizardry to see if you can get the observation,” Yadav said. “In our group, we said, ‘Okay, we know the fundamental physics, let’s give the computers conditions that are similar to Saturn and see whether the fundamental physics spontaneously produced the observation or not.’”

Christopher R. Mankovich, a planetary science researcher at the California Institute of Technology, said that while Yadav and Bloxham’s simulation does not mirror the exact location and shape of Saturn’s storm, it still marks a step forward in researchers’ understanding of the planet.

“There’s definitely work that still needs to be done when it comes to pursuing models like this,” Mankovich said. “But that’s something that the authors note in the study, that this is intended as proof of concept.”

Though the study’s authors concluded that their results support the deep hexagon hypothesis, Mankovich said scientists have yet to reach widespread agreement on the matter.

“There’s not necessarily consensus on the origin of this kind of model,” he said. “While it shows a really good explanation, it also doesn’t necessarily discredit any of the models that appeal to the hexagon being a more shallow phenomenon.”

Yadav said he hopes the simulation will lead to a more refined understanding of the storm.

“Any model that comes up that has a smaller number of assumptions compared to earlier models, that’s a step in the right direction,” Yadav said. “In our model, we were able to basically take a couple of steps in one go.”