Hubble tracks new decagon encircling Saturn's south pole

The NASA/ESA Hubble Space Telescope has revealed a giant, evolving 10-sided atmospheric wave encircling Saturn's south pole, the first large regular-sided jet pattern observed in the planet's southern hemisphere. Researchers traced hints of the structure emerging in 2023 Hubble data before it became clearly defined, with ground-based observations first identifying it in 2024.

The decagon's formation remains unexplained; further study from Hubble and the James Webb Space Telescope, along with computer modeling, is needed to understand how it formed, how long it will persist, and how it compares to Saturn's long-lived northern hexagon.