Move Over, Hexagon: Hubble Reveals a Giant 10-Sided Pattern Swirling Around Saturn’s South Pole

Saturn already had one of the most striking shapes in the solar system: the vast six-sided jet stream at its north pole. In September, astronomers announced that the planet’s other end is getting geometric too.

A decagon in the clouds

Observations from the NASA/ESA Hubble Space Telescope revealed a giant, evolving 10-sided atmospheric wave encircling Saturn’s south pole, centred around 63 degrees south latitude. It is the first large, regular-sided jet pattern ever seen in the planet’s southern hemisphere. The results were published in Science Advances.

Crucially, the pattern is not just a surface marking. Hubble data show it extends through several layers of Saturn’s atmosphere, meaning it is a deep structure embedded in one of the planet’s powerful jet streams.

Hidden in the archives

Looking back through archival images, researchers found the feature was already present in 2023 and has become more pronounced each year since. Ground-based observations collected in 2025 offered stronger evidence that it had formed a decagon, which Hubble then confirmed.

That timing is part of the puzzle. NASA’s Cassini spacecraft, which studied Saturn from 2004 to 2017, did not record a long-lived southern counterpart to the northern hexagon — so something changed after the mission ended.

What happens next

Scientists hope continued monitoring will explain why the decagon suddenly formed and whether it could persist for decades like its northern sibling. For space fans, the images became an instant favourite: proof that even the most familiar planets can still surprise us.

This story was written by the Celestia Times newsroom based on the reporting linked above. Details in developing stories can change; see our corrections policy to report an error. Illustration is original artwork, not a photograph of the events described.