# Hubble Detects a New Ten-Sided Atmospheric Wave Circling Saturn's South Pole URL: https://edufabtech.com/news/hubble-decagon-saturn-south-pole-2026 Section: News · Space Published: 2026-09-12 · Updated: 2026-10-27 Publisher: EduFabTech (https://edufabtech.com) > A paper in Science Advances documents a ten-sided atmospheric wave, a decagon, circling Saturn's south pole inside a fast jet stream — the first such geometric pattern seen in the planet's southern hemisphere. Researchers tracked its emergence from 2023 through 2025 using Hubble and ground-based images, but say they cannot yet explain why it formed now. A paper published on 2 September 2026 in *Science Advances* reports the first large, regular-sided atmospheric wave ever observed circling Saturn's south pole: a ten-sided pattern, or decagon, sitting inside a fast jet stream near 60°S. The finding, announced the same day by the Space Telescope Science Institute in Baltimore, comes from years of NASA/ESA Hubble Space Telescope imaging, and the authors are explicit that they do not yet have an explanation for why the structure appeared when it did. ## What the Hubble data show The team, led by Agustín Sánchez-Lavega of the University of the Basque Country with co-authors including Amy Simon of NASA's Goddard Space Flight Center and Michael Wong of the University of California, Berkeley, pieced the discovery together from Hubble images collected under the Outer Planet Atmospheres Legacy (OPAL) program, which has photographed Saturn, Jupiter, Uranus and Neptune every year for more than a decade. Faint hints of a wavy band near the south pole appear as far back as 2023. Ground-based observations contributed by amateur astronomers Trevor Barry and Jean-Paul Oger, credited in the ESA/Hubble release accompanying the paper, strengthened the case through 2024 and 2025, and a Hubble image taken on 29 August 2025 shows the pattern as a clearly defined, sharpening decagon. According to the paper, the wave is not confined to the cloud tops: it extends through multiple layers of Saturn's atmosphere, tracing the path of a jet stream rather than sitting as a surface cloud feature. ![](https://edufabtech.com/uploads/2026/09/hubble-decagon-saturn-south-pole-2026-2.jpg) *Own work* ## A counterpart to the northern hexagon, but not a twin Saturn's north pole has carried a six-sided jet-stream pattern, the hexagon, for decades; NASA notes it has remained stable for more than 40 years. Researchers had been looking for a southern counterpart since at least 1990, per Sánchez-Lavega's comments accompanying the release, given the rough north-south symmetry expected in Saturn's jet system. The decagon is that counterpart in the loose sense that it is a large, closed, straight-sided wave locked to a polar jet — but it has ten sides rather than six, and unlike the long-settled hexagon, it appears to be new and still strengthening. "We've never seen anything quite like this in Saturn's southern hemisphere," Amy Simon, OPAL's principal investigator, said in the STScI release. "The feature is different — it appears to be strengthening, giving us the rare opportunity to watch a giant atmospheric pattern develop." Simon framed the open question directly: "The question is, why did it suddenly form now when we haven't seen one before?" ## What remains unresolved The paper and the accompanying institutional statements are consistent in treating the discovery as an open problem rather than a settled result. The authors do not yet know what drives the wave; NASA says further Hubble and Webb observations, along with computer modelling, are needed to understand how the decagon formed and how long it may last. Michael Wong is quoted in the release noting that findings like this depend on "years and years of data" rather than a single observation, underscoring that the decagon's long-term stability, unlike the hexagon's four-decade record, is still unknown. ![A side-by-side comparison of Saturn's 40-year-old six-sided northern hexagon and the newly detected ten-sided southern decagon, with each shape's size, discovery date and wind data from the Science Advances study.](https://edufabtech.com/uploads/2026/10/hubble-decagon-saturn-south-pole-2026-3.png) *A side-by-side comparison of Saturn's 40-year-old six-sided northern hexagon and the newly detected ten-sided southern decagon, with each shape's size, discovery date and wind data from the Science Advances study. — EduFabTech · Own work* The authors say further Hubble monitoring, additional James Webb Space Telescope observations, and atmospheric modeling will be needed to determine how the wave formed and whether it will persist. The team plans to continue observing Saturn with Hubble. ## Why it matters beyond Saturn NASA says continued observations could help scientists determine what drives the wave, what it reveals about the atmospheric dynamics of giant planets across the solar system, and how those dynamics may relate to weather patterns on Earth. Having a second large geometric wave on the same planet also lets researchers compare it directly with the long-lived northern hexagon. ## Sources 1. Agustín Sánchez-Lavega, Amy A. Simon, Michael H. Wong, Leigh N. Fletcher, Arrate Antuñano, Ricardo Hueso. (2026). A decagon wave around Saturn's south pole. Science Advances https://doi.org/10.1126/sciadv.aee4251 2. Space Telescope Science Institute. (2026). NASA's Hubble Tracks New Decagon Encircling Saturn's South Pole. Space Telescope Science Institute (news release 2026-022) https://www.stsci.edu/contents/news-releases/2026/news-2026-022 3. NASA Science. (2026). NASA's Hubble Tracks New Decagon Encircling Saturn's South Pole. NASA Science https://science.nasa.gov/missions/hubble/nasas-hubble-tracks-new-decagon-encircling-saturns-south-pole/ 4. ESA/Hubble. (2026). Hubble tracks new decagon encircling Saturn's south pole. European Space Agency https://esahubble.org/news/heic2612/ 5. BBC Sky at Night Magazine. (2026). Something weird's going on at Saturn. Hubble has spotted a 10-sided geometric formation in the planet's clouds. BBC Sky at Night Magazine https://www.skyatnightmagazine.com/news/saturn-decagon-feature-south-pole --- Source page: https://edufabtech.com/news/hubble-decagon-saturn-south-pole-2026 Quote with a link to the source page. © EduFabTech.