Scientists have discovered an enormous 10-sided wave pattern in the icy ammonia clouds over Saturn’s south pole. A Spanish-led team reported Wednesday that the spinning, meandering decagon appears to be even bigger and more unstable than the hexagon of clouds around Saturn’s north pole that’s been visible for decades. This new jet stream formation popped up in the Hubble Space Telescope’s sights in 2023. It’s massive: A single side of the decagon surpasses 10,000 miles. Scientists detailed their findings in the journal Science Advances.