How does the hexagonal vortex, for the lack of a better term, of Saturn's north pole relate to fluid dynamics and how can this hexagon be maintained?
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The Saturn hexagon has had planetary scientists puzzled since its discovery by the Voyager spacecraft decades ago. It's generally agreed that the pattern is caused by a polar vortex similar to that found at the Earth's poles, but the question has been why is the one on Saturn a nearly perfect hexagon in shape?
In 2010 Oxford physicists Ana Claudia Barbosa Aguiar and Peter Read were able to recreate this phenomenon in the lab. They placed a large cylinder of water on a turntable, which represented Saturn's atmosphere as a whole. In the center of the tank they created a smaller vortex to represent a miniature jet stream. By altering the speed of revolution of the model jet stream, “We could create ovals, triangles, squares, almost anything you like,” said Read in an interview with Science magazine (see link to the article below). The larger the difference in speed of rotation between the outer cylinder and the inner jet stream, the fewer sides the polygon had. The ratio of rotations in the model that produced a hexagon correspond to our understanding of rotational speeds on Saturn. The researchers noted that the appearance of such patterns is not at all uncommon in he earth's atmosphere; however the unevenness of surface landforms on Earth tends to break up and change patterns quickly, while on Saturn a lack of same will allow a pattern to persist for a long period of time.
I did read an article on the recreation of this effect by Aguiar and Read, but am perplexed by how and why. Certainly, the vortex begins to explain the how. I just can't get my head around why specific shapes can be formed in the first place. It kind of reminds me of the experiments done in cymatics. What an amazing time in which we live!
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