Astronomers using NASA's Hubble Space Telescope have spotted a massive, 10-sided storm circling Saturn's south pole, a shape never seen before on the gas giant. The discovery, announced in 2026, adds a new twist to our understanding of the planet's turbulent atmosphere.
A Storm With a Strange Shape
The storm, which spans roughly 7,000 miles across, is a jet stream that appears as a polygon in images taken by Hubble on August 29, 2025. While Saturn is known for its six-sided jet stream at its north pole, this new feature at the south pole has 10 sides, making it a decagon. The storm is located in a region where winds blow at speeds of up to 330 miles per hour.
Why Scientists Are Surprised
Saturn's north pole has a long-studied hexagon, a pattern that has persisted for decades. But the south pole was thought to be calmer. The new decagon is not only unexpected but also appears to be a relatively recent development. Hubble images from 2020 showed no such feature, meaning the storm likely formed sometime in the last few years.
What This Means for Saturn
The discovery was made by a team led by planetary scientist Amy Simon of NASA's Goddard Space Flight Center in the United States. They analyzed Hubble's high-resolution images and noticed the distinct 10-sided shape. The storm is thought to be a result of Saturn's internal heat and rotation, which can create these geometric patterns in its atmosphere. For scientists, this is a rare chance to watch a new storm system evolve on a giant planet, offering clues about how such patterns form and change over time.
The finding is significant because it shows that Saturn's atmosphere is more dynamic than previously thought. The existence of a decagon at the south pole, where none was seen before, suggests that the planet's weather systems can shift dramatically. As Hubble continues to monitor Saturn, researchers hope to learn whether this new storm will persist or eventually fade, much like the hexagon at the north pole has done for decades.
