Hubble reveals a 10-sided cloud pattern around Saturn’s south pole
NASA’s Astronomy Picture of the Day has featured Hubble observations of a decagonal cloud pattern, whose cause and long-term stability remain under study.
The Hubble Space Telescope has captured a 10-sided cloud pattern around Saturn’s south pole, featured by NASA in its Astronomy Picture of the Day on 8 September 2026.
The pattern is visible in a composite image taken last year. Saturn’s south pole is marked by an X and surrounded by bands of circulating clouds, with the decagon most prominent in the darker inner regions.
NASA says the geometric boundaries may be caused by waves formed where faster-moving gas away from the pole interacts with slower-moving gas closer to it. The proposed mechanism remains a possibility rather than a confirmed explanation.
The observation echoes, but does not replicate, Saturn’s better-known northern feature: a six-sided cloud pattern identified in Voyager data and observed for more than 40 years.
Scientists are expected to continue studying whether the southern decagon remains stable over time. Unlike a solid structure, it is a pattern in Saturn’s clouds and gas.
