# Hubble and ground telescopes find a ten-sided wave near Saturn's south pole at 58–63°S

- Published: 2026-11-10 16:44 UTC
- Section: Sky & Space › Astronomy
- Tags: Saturn decagon, ten-sided wave on Saturn, Hubble Saturn 2025, Saturn south pole, Saturn north hexagon, planetary jet stream, Rossby-type meandering wave, Outer Planet Atmospheres Legacy
- URL: https://realtech.media/news/rt-b96c4f106c6e3e5944511609_hubble_and_ground/

**Images from 2025 show a decagonal wave in Saturn's southern jet. It drifts east at 2.5 m/s, and no similar wave had been reported in the southern hemisphere before.**

![Hubble and ground telescopes find a ten-sided wave near Saturn's south pole at 58–63°S](https://realtech.media/media/2026/11/6ce051101bce1462.jpg)
*NASA, ESA, J. Clarke (Boston University), and Z. Levay (STScI), Wikimedia Commons, Public domain*

A decagonal wave has been found in Saturn's atmosphere near the south pole, according to a study in Science Advances. Ground-based and Hubble Space Telescope images obtained in 2025 show a ten-sided pattern at planetographic latitudes of about 58°S to 63°S [1]. Until now, no similar wave had been reported in Saturn's southern hemisphere or elsewhere on the planet, apart from the north polar region [1].

## What the images show

Saturn has a long-lived, nearly stationary hexagonal wave close to its north pole, coupled to an intense eastward jet. It has been observed for decades, and the northern hexagon has been seen for more than four decades [1]. The new decagon is traced by clouds in the southern jet, whose peak lies at 60.5°S.

Hubble images from 2023 and 2024 showed the vertices with weaker albedo contrasts and linear sides of the decagon. The authors take this to mean that the phenomenon is evolving [1]. Amateur observers contributed images in 2024, and the shape became much clearer in the 2025 observations. The data come from Hubble's Outer Planet Atmospheres Legacy program, which has tracked Saturn since 2018, and images taken through different filters show the pattern at different levels of the atmosphere.

## Motion and possible origin

The decagon moves eastward at 2.5 meters per second. This is much slower than the zonal jet at 60.5°S, where the wind speed is 116 meters per second [1]. The longitudes of the vertices oscillate with a period of 32 days and amplitudes of 4.6° to 8.4° [1]. NASA's Cassini spacecraft saw short-lived shapes in the southern jet in 2004, but not a long-lasting pattern like this one.

From these properties, the authors suggest that the decagon could be a large-scale meandering wave. It would be trapped vertically and confined meridionally by the curvature of the dominant jet [1]. Shallow water model simulations suggest two possible origins. The decagon may have arisen from a spatially periodic disturbance in the jet peak, or it may have been driven by a dark anticyclonic vortex immediately to the north [1]. According to the publication's retelling, this dark storm lies near 55°S.

## Sources

1. [Science Advances](https://doi.org/10.1126/sciadv.aee4251)
2. [knowridge.com](https://knowridge.com/2026/11/hubble-spots-a-giant-ten-sided-wave-near-saturns-south-pole)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-b96c4f106c6e3e5944511609_hubble_and_ground/