Using the James Webb Space Telescope, scientists uncovered bizarre atmospheric structures on Saturn, including drifting “dark beads” in the ionosphere and an asymmetric star pattern in the stratosphere.
Both may connect to Saturn’s iconic hexagonal storm, but their true nature remains a mystery.
Webb Telescope Unveils Saturn’s Atmospheric Mysteries
A new investigation of Saturn’s upper atmosphere, carried out with the James Webb Space Telescope (JWST), has uncovered strikingly unusual features never before observed on any planet in the Solar System. The findings were unveiled last week by Professor Tom Stallard of Northumbria University during the EPSC-DPS2025 Joint Meeting in Helsinki.
“This opportunity to use JWST was the first time we have ever been able to make such detailed near-infrared observations of Saturn’s aurora and upper atmosphere. The results came as a complete surprise,” said Professor Stallard.
This video reveals how the buildings noticed in Saturn’s ionosphere and stratosphere relate to at least one one other. Starting with the aurora at 1100 km, the brightness is elevated to disclose the darkish bead-like options. The video then fades into the star-arm shapes inside the underlying 600 km layer. The darkest beads in the ionosphere seem to line up with the strongest arm beneath it, however it’s not clear if that is coincidental, or if it suggests coupling between Saturn’s lowest and highest layers of the environment. Credit: NASA/ESA/CSA/Stallard et al 2025.
Beads, Stars, and the Unexpected Patterns
“We anticipated seeing emissions in broad bands at the various levels. Instead, we’ve seen fine-scaled patterns of beads and stars that, despite being separated by huge distances in altitude, may somehow be interconnected – and may also be linked to the famous hexagon deeper in Saturn’s clouds. These features were completely unexpected and, at present, are completely unexplained.”
The discovery was made by an international collaboration of 23 researchers from the UK, US, and France, who observed Saturn for a continuous 10-hour stretch on November 29, 2024, while the planet rotated under JWST’s gaze.
Hydrogen Ions and Methane Molecules Under the Lens
The team focused on detecting infrared emissions by a positively charged molecular form of hydrogen, H3+, which plays a key role in reactions in Saturn’s atmosphere and so can provide valuable insights into the chemical and physical processes at work. JWST’s Near Infrared Spectrograph allowed the team to simultaneously observe H₃⁺ ions from the ionosphere, 1,100 kilometers above Saturn’s nominal surface, and methane molecules in the underlying stratosphere, at an altitude of 600 kilometers.
In the electrically charged plasma of the ionosphere, the team observed a series of dark, bead-like features embedded in bright auroral halos. These structures remained stable over hours but appeared to drift slowly over longer periods.
This video of Saturn’s stratosphere reveals a fancy and extremely shocking star-shaped construction, revealed for the primary time by JWST’s unprecedented sensitivity. Four darkish bands lengthen away from the polar area, showing to make up 4 out of six arms that align with Saturn’s well-known hexagon inside the decrease environment. At this level, it’s unknown why the darkish arms are flowing in the direction of the equator, or why two of the arms are lacking, however the causes could also be related to the advanced bead buildings noticed many a whole bunch of kilometers above in the ionosphere. Credit: NASA/ESA/CSA/Stallard et al 2025.
Lopsided Star Over Saturn’s North Pole
Around 500 kilometers decrease, in Saturn’s stratosphere, the staff found an uneven star-shaped function. This uncommon construction prolonged out from Saturn’s north pole in the direction of the equator. Only 4 of the star’s six arms have been seen, with two mysteriously lacking, making a lopsided sample.
“Saturn’s upper atmosphere has proven incredibly difficult to study with missions and telescope facilities to date due to the extremely weak emissions from this region,” mentioned Professor Stallard. “JWST’s incredible sensitivity has revolutionized our ability to observe these atmospheric layers, revealing structures that are completely unlike anything we’ve seen before on any planet.”
Connection to Saturn’s Hexagon Storm
The staff mapped the precise areas of the options and located that they overlaid the identical area of Saturn at completely different ranges, with the star’s arms showing to emanate from positions instantly above the factors of the storm-cloud-level hexagon. This means that the processes which can be driving the patterns could affect a column stretching proper by way of Saturn’s environment.
“We think that the dark beads may result from complex interactions between Saturn’s magnetosphere and its rotating atmosphere, potentially providing new insights into the energy exchange that drives Saturn’s aurora. The asymmetric star pattern suggests previously unknown atmospheric processes operating in Saturn’s stratosphere, possibly linked to the hexagonal storm pattern observed deeper in Saturn’s atmosphere,” mentioned Professor Stallard.
This video of Saturn’s ionosphere highlights the distinction in brightness between JWST’s infrared observations of the aurora and the dim bead options. The aurora itself is comparatively weak, virtually unattainable to picture from Earth, needing hours of integration time to look at utilizing ground-based information. However, the auroral options are at the very least 4 occasions brighter than the brightest elements of the darkish bead options, so to correctly present the hidden options, the aurora are fully saturated. Credit: NASA/ESA/CSA/Stallard et al 2025.
Coincidence or Cosmic Link?
“Tantalizingly, the darkest beads in the ionosphere appear to line up with the strongest star-arm in the stratosphere, but it’s not clear at this point whether they are actually linked or whether it’s just a coincidence.”
While each options might have vital implications for understanding atmospheric dynamics on fuel large planets, extra work is required to offer explanations for the underlying causes.
Seasonal Changes and Urgency for Follow-Up
The staff hopes that further time could also be granted in future to hold out follow-up observations of Saturn with JWST to additional discover the options. With the planet at its equinox, which happens roughly each 15 Earth years, the buildings could change dramatically as Saturn’s orientation to the Sun shifts and the northern hemisphere strikes into autumn.
“Since neither atmospheric layer can be observed using ground-based telescopes, the need for JWST follow-up observations during this key time of seasonal change on Saturn is pressing,” Stallard added.
References:
“JWST’s transformational observations of Giant Planet ionospheres” by Tom Stallard, Henrik Melin, Luke Moore, Emma Thomas, Katie Knowles, Paola Tiranti and James O’Donoghue, 8 July 2025, EPSC Abstracts.
DOI: 10.5194/epsc-dps2025-817
“JWST/NIRSpec Detection of Complex Structures in Saturn’s Sub-Auroral Ionosphere and Stratosphere” by Tom S. Stallard, Luke Moore, Henrik Melin, Omakshi Agiwal, M. Nahid Chowdhury, Rosie E. Johnson, Katie L. Knowles, Emma M. Thomas, Paola I. Tiranti, James O’Donoghue, Khalid Mohamed, Ingo Mueller-Wodarg, Leigh Fletcher, Imke de Pater, Thierry Fouchet and Sarah V. Badman, 28 August 2025, Geophysical Research Letters.
DOI: 10.1029/2025GL116491
The Saturn analysis was supported by grants from the Science and Technology Facilities Council (STFC), NASA Solar System Workings program, and the European Research Council. The examine represents a part of JWST’s ongoing revolutionary observations of our photo voltaic system’s planets.
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