Astronomers have discovered a giant, 10-sided atmospheric wave surrounding Saturn’s south pole. The finding, detailed in the journal Science Advances, represents the first time a large, regular-sided jet pattern has been documented in the planet's southern region. While it shares visual similarities with the long-standing hexagon at Saturn’s north pole, researchers note that this new feature appears to be actively strengthening.

The discovery emerged from a combination of ground-based imagery and data from NASA’s Hubble Space Telescope. Initial signs of an undulating band were spotted in 2024 by researchers and amateur astronomers contributing to the Planetary Virtual Observatory Laboratory. Subsequent analysis of Hubble’s Outer Planet Atmospheres Legacy (OPAL) program data confirmed the structure's presence dating back to 2023.

"We've never seen anything quite like this in Saturn's southern hemisphere," said Amy Simon, a study co-author based at NASA’s Goddard Space Flight Center. "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."

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The wave is situated within a powerful jet stream and extends across multiple atmospheric layers, suggesting it is a deep-seated structure rather than a shallow cloud formation. Lead author Agustín Sánchez-Lavega of the University of the Basque Country noted that previous missions, including the Cassini spacecraft, showed no evidence of such a formation in the south during its tenure from 2004 to 2017.

Scientists intend to utilize further observations from Hubble and the James Webb Space Telescope, alongside computer modeling, to determine the origins of the decagon and whether it will stabilize into a permanent feature. The OPAL program, which provides annual snapshots of outer planets, remains central to monitoring how this phenomenon evolves over time.

Source: NASA