For decades, Saturn has fascinated scientists with its rings, storms, and unusual north-pole hexagon.
Now, the James Webb Space Telescope (JWST) has uncovered something even stranger: dark bead-like features and lopsided star patterns high in the planet’s atmosphere.
These newly discovered structures are unlike anything seen before on Saturn—or on any other planet.
The discovery was announced by Professor Tom Stallard of Northumbria University in the UK at a major planetary science conference in Helsinki and published in Geophysical Research Letters.
“This was the very first time we’ve been able to take such detailed near-infrared observations of Saturn’s aurora and upper atmosphere,” said Stallard.
“We expected to see fairly broad bands of emissions at different levels.
Instead, what we found were fine-scale beads and star shapes that don’t make sense yet. They may even be linked to the famous hexagon deeper in Saturn’s clouds.”
A 10-hour look at Saturn
The results come from a 10-hour JWST observation on 29 November 2024, during which Saturn rotated beneath the telescope’s gaze.
An international team of 23 scientists from the UK, US, and France studied infrared emissions from a special ion of hydrogen called H₃⁺. This molecule plays an important role in Saturn’s atmosphere and provides clues about chemical and physical processes happening there.
JWST’s Near Infrared Spectrograph let the researchers view two layers at once: the ionosphere, about 1,100 kilometers above Saturn’s visible surface, and the stratosphere, about 600 kilometers up.
Dark beads and lopsided stars
In the ionosphere, the team spotted strings of dark, bead-like shapes sitting inside bright auroral halos.
These beads stayed steady for hours but slowly drifted over time.
Closer to the cloud tops, in the stratosphere, the researchers saw a star-shaped feature stretching out from the north pole toward the equator. Strangely, the star only had four arms instead of six, creating an uneven, lopsided pattern.
Mapping the features showed that they were stacked above the same regions of Saturn, suggesting they might be connected. The star’s arms seemed to line up with points of Saturn’s north-pole hexagon, hinting that processes deep in the clouds could extend all the way up through the atmosphere.
“The beads might be caused by complex interactions between Saturn’s magnetic field and its rotating atmosphere,” Stallard explained.
“Meanwhile, the strange star pattern in the stratosphere may reveal an entirely new process we don’t yet understand.”
Even more intriguing, the darkest ionospheric beads appear to match up with the strongest of the star’s arms. Scientists don’t yet know if this is coincidence or evidence of a real link between the two layers.
Saturn’s upper atmosphere has always been difficult to study because its emissions are so faint. Until JWST, no telescope could capture such sensitive measurements. These results not only reveal Saturn’s atmosphere in greater detail than ever before, but they also raise brand-new questions about how giant planets work.
The research team hopes for more observing time with JWST. Saturn is currently at its equinox, a rare moment that happens every 15 Earth years, when sunlight falls evenly across the planet.
As Saturn’s northern hemisphere tilts into autumn, these mysterious beads and stars could shift or even vanish, making now a critical time for follow-up observations.
“Ground-based telescopes simply can’t see these layers,” Stallard said. “We urgently need JWST to look again as Saturn’s seasons change, so we can find out what’s really driving these patterns.”
With its rings, storms, and now bead-and-star mysteries, Saturn has once again proven itself one of the most captivating worlds in our solar system.
