The James Webb Space Telescope (JWST) has revealed previously unseen structures within Saturn's atmosphere, including dark, bead-like features and an asymmetric star-shaped pattern at the planet's north pole. These findings, published on August 28, 2025, offer new insights into Saturn's atmospheric dynamics. Professor Tom Stallard of Northumbria University led the study, which utilized JWST's Near Infrared Spectrograph for a 10-hour observation on November 29, 2024. The telescope's advanced instruments allowed for unprecedented detail in observing Saturn's aurora and upper atmosphere, capturing phenomena never before witnessed on any planet.
High in Saturn's ionosphere, approximately 1,100 kilometers above the planet's surface, the JWST detected a series of dark, bead-like structures embedded within bright auroral halos. These formations remained stable for hours but exhibited a slow drift over longer observation periods. Simultaneously, about 500 kilometers lower in the stratosphere, the telescope observed an unusual star-shaped feature. This pattern was asymmetric, with only four of the six expected arms visible, creating a lopsided appearance.
Professor Stallard noted that these fine-scaled patterns of beads and stars, despite their vast separation in altitude, may be interconnected and possibly linked to the planet's famous hexagonal storm pattern observed deeper within its atmosphere. The study suggests that the dark beads might stem from complex interactions between Saturn's magnetosphere and its rotating atmosphere, potentially illuminating the energy exchange that powers Saturn's aurora. The asymmetric star pattern, conversely, points to previously unknown atmospheric processes at play in the stratosphere, possibly connected to the hexagon.
Intriguingly, the darkest beads in the ionosphere appear to align with the strongest arm of the star pattern in the stratosphere, though the exact nature of this connection remains unclear. These discoveries challenge existing models of Saturn's atmosphere and raise new questions about its magnetic and atmospheric dynamics. The team hopes to conduct further observations, particularly as Saturn approaches its equinox, an event occurring every 15 Earth years, which may cause these atmospheric features to evolve dramatically. The unique capabilities of the JWST are crucial for studying these atmospheric layers, as they are not observable with ground-based telescopes.