NASA's Hubble Space Telescope and large ground-based observatories detected a new 10-sided atmospheric wave surrounding Saturn's southern skies. ^[1] An international team led by Agustín Sánchez-Lavega confirmed the discovery of a 10-sided atmospheric figure known as the Saturn decagon swirling over Saturn's south pole. ^[2] Amy Simon, a co-author of the study based at NASA's Goddard Space Flight Center, stated that the decagon seems to have just formed recently and questioned why it appeared now when it had not been seen before. ^[3] The decagon is not a ring of solid clouds but a giant atmospheric wave, a repeating bend in the winds that runs all the way around the planet. ^[4] The decagon, which has 10 corners and 10 long sides, rings Saturn's southern mid-latitudes where a powerful jet stream races around the globe. ^[5] Amy Simon, study co-author and OPAL principal investigator at NASA's Goddard Space Flight Center, stated that this feature is different from the northern hexagon and appears to be strengthening. ^[6] NASA's Hubble Space Telescope first captured faint hints of a 10-vertex polygonal shape in 2023, which sharpened into a fully defined decagon structure in images taken in August-September 2025. ^[7] The discovery team officially published their findings in the journal Science Advances in September 2026. ^[8]