Scientists Identify Decagonal Jet Stream Over Saturn's South Pole
A team of researchers has detected a massive ten-sided wave pattern in Saturn's southern polar clouds, a formation larger and more dynamic than the previously known hexagon at the north pole.
Scientists using the Hubble Space Telescope have identified a decagonal jet stream in the icy ammonia clouds above Saturn's south pole. The ten-sided pattern, first seen in 2023, appears larger than the planet's well-known north-pole hexagon and may have formed between 2017 and 2023 when the southern pole was out of view.
Lead author Agustín Sánchez-Lavega of the University of the Basque Country said the discovery suggests the hexagon is not as unique as previously thought. Measurements from the European Southern Observatory’s Very Large Telescope in Chile indicate the decagon is migrating eastward at about 6 mph (10 kph), whereas the hexagon remains nearly stationary.
Leigh Fletcher of the University of Leicester noted that Saturn continues to reveal unexpected atmospheric phenomena. Comparing the two polar structures could improve understanding of weather patterns on gas giants, the researchers said.
The findings, published in Science Advances, raise questions about the longevity of the decagon and its possible connection to polygonal cyclone arrangements observed on Jupiter. Ongoing observations of Saturn’s southern hemisphere are expected to provide further detail on the feature’s evolution.