One of the most bizarre weather patterns ever discovered is a hexagon-shaped storm located at Saturn’s northern pole.
The hexagon at Saturn was first seen by NASA’s Voyager 1 and 2 spacecraft when they first visited the planet more than two decades ago. More recently, the Saturn hexagon was imaged in great detail by NASA’s Cassini spacecraft, currently in orbit around Saturn. The Saturn hexagon is exactly that; a hexagon-shaped band of clouds sitting right at Saturn’s north pole. The hexagon is 25,000 km (15,000 miles) across. In fact, you could nearly fit 4 planets the size of Earth in there.
We have a similar feature here on Earth called the polar vortex. But on Earth, the polar vortex winds travel in a circular pattern around the north pole. The Saturn hexagon rotates exactly the same speed as Saturn rotates, and has been since it was first discovered by Voyager more than 25 years ago.
The northern hexagon is dramatically different from Saturn’s southern pole, which has a huge hurricane with a giant eye. Astronomers originally believed that there wasn’t a hexagon at Saturn’s south pole, but new research found one there too.
So why is the hexagon there? Astronomers have no idea. Here’s what Kevin Baines, atmospheric expert and member of Cassini’s visual and infrared mapping spectrometer team at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. had to say, “This is a very strange feature, lying in a precise geometric fashion with six nearly equally straight sides. We’ve never seen anything like this on any other planet. Indeed, Saturn’s thick atmosphere where circularly-shaped waves and convective cells dominate is perhaps the last place you’d expect to see such a six-sided geometric figure, yet there it is.”
We have written many articles about Saturn for Universe Today. Here’s the article where we first announced the updated images of the Saturn hexagon. And here’s an article with images of a hexagon at Saturn’s southern pole.
We have recorded a podcast just about Saturn for Astronomy Cast. Click here and listen to Episode 59: Saturn.