Mysterious decagon-shaped wave discovered in Saturn's atmosphere
Scientists face an unexplained phenomenon in Saturn's southern polar region.
1Discovery of the decagon
The Hubble Space Telescope detected a 10-sided (decagon) wave structure over Saturn's south pole on August 29, 2025. Visible in 763-nanometer infrared wavelength images, this formation represents a previously unseen atmospheric phenomenon. Physicist Agustín Sánchez-Lavega from Bilbao School of Engineering emphasized that this structure has no parallel in Earth's atmosphere.
2Timeline of appearance
Initial signs of the decagon wave appeared in Hubble images from 2023. By summer 2025, it had fully formed in recent photographs. The absence of such structure in NASA's Cassini mission data (which ended in 2017) suggests the phenomenon is relatively new. Researchers predict the feature may become more pronounced by 2032.
3Northern counterpart
The discovery bears similarities to the hexagonal atmospheric wave found at Saturn's north pole in the 1980s. However, the southern decagon differs in both edge count and formation mechanism. A key distinction is that while the hexagon remains stable, the decagon appears to still be evolving.
4Possible causes
Scientists theorize a storm with a high-pressure center might have disrupted gas flows. Some suggest a process similar to Jupiter's Great Red Spot may have produced different results on Saturn. Other explanations include instability in the jet stream or waves originating from deeper atmospheric layers.
5Observation techniques
The discovery was made using polar projection images at 763 nm (red) and 889 nm (methane absorption band) wavelengths. The decagon, marked by yellow arrows, becomes visible between latitude circles shown as blue dashed lines. This technique provides better understanding of atmospheric structures' three-dimensional behavior.
6Seasonal influences
Researchers believe seasonal insolation cycles at the south polar region may contribute to the structure's formation. As solar radiation peaks at the decagon's latitude around 2032, the phenomenon may intensify. This supports theories about how Saturn's 29.5-year orbital period affects atmospheric dynamics.
7Comparative planetology
The scientific community puzzles over why such features appear only on Saturn. The absence of similar structures on other gas giants like Jupiter suggests unique atmospheric conditions on Saturn. Latitude differences between the two planets might explain this atmospheric diversity.
8Scientific significance
This discovery opens new windows for understanding dynamic processes in planetary atmospheres. It particularly expands our knowledge about atmospheric waves' origins and evolution in gas giants. Published in Science Advances, the study provides valuable guidance for future space observation missions.