{"id":453789,"date":"2026-09-04T21:58:24","date_gmt":"2026-09-04T21:58:24","guid":{"rendered":"https:\/\/www.newsbeep.com\/us-ca\/453789\/"},"modified":"2026-09-04T21:58:24","modified_gmt":"2026-09-04T21:58:24","slug":"decagon-wave-emerges-near-saturns-south-pole","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/us-ca\/453789\/","title":{"rendered":"Decagon Wave Emerges Near Saturn\u2019s South Pole"},"content":{"rendered":"

\"Two
\nTwo views of Saturn from NASA\u2019s Hubble Space Telescope reveal a giant, evolving 10-sided atmospheric wave encircling the planet\u2019s south pole. Credit: Image: NASA, ESA, STScI, Agustin S\u00e1nchez-Lavega (UPV), Amy Simon (NASA-GSFC), Michael Wong (UC Berkeley); Image Processing: Alyssa Pagan<\/p>\n

Since its discovery in 1980, the hexagonal polar jet stream that surrounds Saturn\u2019s north pole has perplexed scientists. The symmetrical six-sided polygonal wave has been duplicated in laboratory experiments by spinning a circular tank filled with liquid, but the reasons for its formation on Saturn and for its gradual color shift from blue to gold are still being debated. Now, scientists with the\u00a0Outer Planet Atmospheres Legacy<\/a>\u00a0(OPAL) program, have uncovered another Saturnian mystery. They found that a blue decagon has recently emerged surrounding the planet\u2019s south pole.\u00a0<\/p>\n

In a\u00a0paper\u00a0<\/a>published today in Science Advances, scientists from the UC Berkeley Space Sciences Laboratory (SSL), NASA\u2019s Goddard Space Flight Center,\u00a0and the University of the Basque Country, described tracking the gradual emergence of the ten-sided jet stream wave by examining Hubble Space Telescope images going back to 2023. Features like Jupiter\u2019s Great Red Spot, a cyclone which has persisted through nearly 200 years of observation, can create the impression that the outer planets are timeless and unchanging. Saturn\u2019s decagon shows how changeable these planets can be.\u00a0<\/p>\n

\u201cA few years ago, this feature wasn\u2019t there,\u201d said\u00a0Michael Wong<\/a>, study co-author and a researcher with SSL. \u201cIt demonstrates the importance of regular observation of the outer planets.\u201d<\/p>\n

After the discovery of Saturn\u2019s northern hexagon, scientists were curious when no southern polygonal wave was discovered. In 2004, NASA\u2019s Cassini spacecraft imaged Saturn\u2019s entire southern hemisphere. It didn\u2019t find a hexagon, but it did find that the circular band of east-to-west jet currents at 60.5\u00b0S showed perturbations that had a\u00a0polygonal appearance<\/a>, but that feature lasted for no more than a few days and was never seen again before the Cassini mission ended with a planned dive into Saturn\u2019s atmosphere in 2017. With Cassini out of the picture, an observation gap opened on Saturn, and the OPAL project stepped in to fill it.\\<\/p>\n

\"A
\nA person in a cleanroom suit working on the Wide Field Camera 3 in a cleanroom. Credit: NASA<\/p>\n

Inspiration for the OPAL project can be traced to 2009. At the time, Wong was a visiting scientist with the Space Telescope Science Institute, participating in the calibration of Hubble\u2019s recently installed\u00a0Wide Field Camera 3<\/a>(WFC3). A large impact event was observed on Jupiter that year, and Wong trained the WFC3 on the planet, capturing the first\u00a0science images<\/a>\u00a0taken by the instrument, but long gaps in Hubble outer planet observations followed with no images of Jupiter taken in 2011 and 2013. Those gaps led\u00a0Amy Simon<\/a>, the principal investigator of OPAL and a planetary scientist at NASA Goddard, make the case for yearly WFC3 survey of the four outer planets: Jupiter, Saturn, Uranus, and Neptune. The project was approved, with Saturn observations starting in 2018 following the end of the Cassini mission.<\/p>\n

OPAL\u2019s annual observations began bearing fruit in the years that followed. In 2021, the OPAL team \u2014 consisting of Wong, Simon and\u00a0Glenn Orton<\/a>, a senior research scientist at NASA\u2019s Jet Propulsion Laboratory \u2014\u00a0found<\/a>\u00a0that wind speeds in Jupiter\u2019s Great Red Spot were increasing. In 2023, they\u00a0found<\/a>\u00a0that Uranus\u2019 northern polar hood was brightening over time, and this July, they\u00a0published<\/a>\u00a0observations on a complete lifecycle of one of the dark spot cyclones on Neptune.<\/p>\n

\"Side-by-side
\nSaturn\u2019s Hexagon. These natural color views from NASA\u2019s Cassini spacecraft compare the appearance of Saturn\u2019s north-polar region in June 2013 and April 2017. Credit: NASA\/JPL-Caltech\/Space Science Institute\/Hampton University<\/p>\n

Saturn\u2019s decagon was first noticed by Agust\u00edn S\u00e1nchez-Lavega, lead author of the study and a researcher at the University of the Basque Country, which accepts ground-based images from contributors through its\u00a0Planetary Virtual Observatory Laboratory<\/a>\u00a0(PVOL). An image received by PVOL in 2024 contained a perturbation similar to the one Cassini observed twenty years earlier, and S\u00e1nchez-Lavega got in touch with the OPAL team to study Hubble\u2019s higher-resolution images of the southern hemisphere. When Hubble\u2019s images from 2024 and 2025 were projected onto a polar view, the decagon was clearly visible at some 63\u00b0S.<\/p>\n

Reviewing the images through different filters revealed that the decagon wave has a 3-dimensional structure. The part of the wave that is visible to the naked eye is in Saturn\u2019s upper troposphere, and the winds that create it are moving at some 400 kilometers per hour. S\u00e1nchez-Lavega developed a shallow water equation model to show how a decagon could emerge in turbulent liquid, but most aspects of Saturn\u2019s decagon remain mysterious. The composition of the aerosols that give the wave its blue color is not known, and neither is the structure of the wave as it extends lower into the atmosphere.<\/p>\n

\"Two
\nPolar projections of Saturn\u2019s southern hemisphere at two wavelengths: red at 763 nm and a methane absorption filter at 889 nm. The decagon is indicated by a yellow arrow. The dashed lines show the circles of latitude in blue, with their values indicated. Images obtained on 29 August 2025 by the Hubble Space Telescope. Credit: EHU\/NASA\/ESA<\/p>\n

The study authors may be closer to answering the mystery of the decagon\u2019s formation. They noted that it is located just to the south of an anticyclone vortex at some 55\u00b0S. The compact vortex was first observed in 2023, but it darkened precipitously in 2025, just before the decagon emerged.\u00a0<\/p>\n

\u201cPerhaps the vortex caused the initial perturbation, and then the balance of forces caused the persistent decagon,\u201d said Wong. \u201cWe really need more detailed simulations of its 3-D structure to know for sure.\u201d<\/p>\n

Correction: A previous version of this story incorrectly\u00a0listed\u00a0some study authors from the Space Telescope Science Institute rather than NASA\u2019s Goddard Space Flight Center.<\/p>\n","protected":false},"excerpt":{"rendered":"Two views of Saturn from NASA\u2019s Hubble Space Telescope reveal a giant, evolving 10-sided atmospheric wave encircling the…\n","protected":false},"author":2,"featured_media":453790,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[34],"tags":[139452,143,145,144,139450,139451],"class_list":["post-453789","post","type-post","status-publish","format-standard","has-post-thumbnail","category-oakland","tag-faculty-excellence","tag-oakland","tag-oakland-headlines","tag-oakland-news","tag-research-berkeley","tag-uc-berkeley-research"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/posts\/453789","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/comments?post=453789"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/posts\/453789\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/media\/453790"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/media?parent=453789"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/categories?post=453789"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/tags?post=453789"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}