NASA has discovered a strange atmospheric wave at Saturn’s south pole

NASA’s Hubble Space Telescope has observed a strange, decagon-shaped atmospheric wave at Saturn’s south pole—the first regular, multi-sided pattern ever observed in that region.

In a study recently published in the journal *Science Advances*, researchers analyzed this unusual formation and identified signs of a new atmospheric phenomenon on the gas giant.

A similar hexagon-shaped wave has long existed at Saturn’s north pole, but the southern feature differs in several important ways.

Hubble observations conducted between 2023 and 2025 allowed the team to gradually identify this decagonal structure.

“We have never seen anything like this in Saturn’s southern hemisphere,” said co-author Amy Simon, principal investigator of NASA’s OPAL program at the Goddard Space Flight Center in Greenbelt, Maryland.

Since its launch into low Earth orbit in 1990, Hubble has observed the Solar System and revealed new details about our neighboring planets. One of its key projects is the Outer Planet Atmospheres Legacy (OPAL) program, which began with observations of Uranus in 2014 and now provides crucial data for this discovery, thanks to high-resolution images that clarified the vague hints seen by ground-based observatories.

As the seasons changed on Saturn, its south pole became better positioned for ground-based observatories. In images submitted to the Planetary Virtual Observatory Laboratory, amateur astronomers Trevor Barry and Jean-Paul Oger, along with Agustín Sánchez-Lavega from the University of the Basque Country in Spain, noticed something interesting.

The researchers initially identified a wavy band near the south pole, which in 2025 ground-based images began to suggest a decagonal structure. Hubble’s clear images ultimately confirmed the shape.

“Given the symmetry of Saturn’s jet-stream system in the northern and southern hemispheres, we have been searching for a counterpart to the northern hexagon at the south pole since 1990. Images from NASA’s Cassini spacecraft, which orbited Saturn between 2004 and 2017, showed no sign of a stable formation. Hubble data confirmed its presence beginning in 2023,” said lead author Agustín Sánchez-Lavega.

The wave is an interesting three-dimensional structure that extends across several atmospheric layers within one of the planet’s jet streams.

Hubble can observe at different wavelengths, and the apparent position of the decagon changes depending on how deeply the observations penetrate into the atmosphere.

“The most intriguing part for me is that it appears to have formed recently. The question is: why did it form now, when we have never seen it before?” he emphasized.

The discovery of the decagonal wave is only the first step. Further observations and computer models will be needed to fully understand the phenomenon. Questions remain about how it formed, how long it may last, and how similar it is to the northern hexagon.

The team will closely monitor whether the shape evolves or maintains its decagonal structure. Future studies could provide important new insights into the atmospheric dynamics of gas giants and what they can tell us about Earth’s atmosphere.

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