Hubble spots mysterious 10-sided pattern forming around Saturn's south pole

NASA's Hubble Space Telescope has revealed a giant 10-sided pattern encircling Saturn's south pole, giving scientists a rare opportunity to watch an unusual feature develop on another planet.

The unusual pattern is actually a huge atmospheric wave embedded in one of Saturn 's powerful jet streams. It extends through multiple layers of the atmosphere, showing that it is more than a cloud-level feature.

The discovery marks the first time that a large pattern with regular sides has been observed around Saturn's south pole. The findings were published Wednesday in the journal Science Advances .

"We've never seen anything quite like this in Saturn's southern hemisphere," NASA scientist and study co-author Amy Simon said . "The northern hexagon has been there every time we've looked for more than 40 years. This feature is different - it appears to be strengthening, giving us the rare opportunity to watch a giant atmospheric pattern develop."

Saturn's north pole is already home to another unusual atmospheric feature: a six-sided pattern in the clouds. Scientists have observed that feature for decades, but until now, nothing similar had been confirmed around the planet's south pole.

Hints of the new 10-sided pattern appeared in Hubble observations as early as 2023, NASA said. Ground-based images from amateur astronomers helped reveal the unusual shape in 2024, with additional observations in 2025.

Hubble provided a much sharper view of the feature because it orbits above Earth's atmosphere, which can distort images taken from the ground.

"The most intriguing part to me is that this seems to have just formed recently," Simon said. "The question is, why did it suddenly form now when we haven't seen one before?"

Saturn's changing seasons also played a role in the discovery. As the planet moved through its orbit, its south pole gradually tilted back into view from Earth, giving astronomers a better opportunity to study the region.

Scientists still do not know what caused the 10-sided pattern or how long it will last. That makes its apparent recent formation particularly valuable, since researchers may be able to watch the feature change rather than discovering it only after it has become established.

NASA plans to continue observing Saturn with Hubble and the James Webb Space Telescope. Future observations could reveal whether the 10-sided pattern eventually settles into a long-lived formation similar to the northern hexagon or continues to change over time.