🪐 Saturn Has Grown a Giant 10-Sided Storm Pattern

Saturn has been famous for decades for the enormous hexagon circling its north pole.

Now Hubble has discovered something even stranger at the opposite end of the planet: a vast decagon — a 10-sided atmospheric wave — surrounding Saturn’s south pole.

The structure sits roughly between 58° and 63° south latitude inside a jet stream moving at about 400 km/h. The decagon itself drifts much more slowly around the planet, at about 10 km/h, while its corners oscillate back and forth over periods of roughly a month. Multiwavelength Hubble observations show that the pattern extends through several atmospheric levels rather than existing as a superficial cloud shape.

What makes the discovery particularly intriguing is that it seems to be new. Cassini saw no comparable structure before its mission ended in 2017. Hubble data reveal faint hints beginning in 2023, with the ten-sided shape becoming increasingly distinct in 2024 and 2025. Astronomers may therefore be watching a giant planetary wave form almost in real time.

Scientists do not yet know why Saturn produces geometric atmospheric structures at all. Models suggest the decagon may be a huge wave trapped inside the jet stream, possibly triggered by an instability or a nearby vortex. But why the north settled on six sides and the south apparently chose ten remains unexplained.

Earth gets hurricanes.

Saturn apparently prefers geometry.

#Saturn #Hubble #Astronomy #PlanetaryScience #Space #Science

https://www.science.org/doi/10.1126/sciadv.aee4251