Thirty years ago, scientists discovered an intriguing structure on Saturn's north pole. Nothing even resembling this structure has ever been seen on any other planet … in the entire Universe.

The six-sided structure, nicknamed 'the hexagon', is about 32,000 km in diameter and extends about 100 km down into Saturn's atmosphere.

Scientists have figured out that it's actually a cloud pattern created by a gigantic hurricane roiling at the center of the north pole. The eye of this hurricane is 50 times bigger than a typical hurricane eye on Earth.

Using NASA's Voyager and Cassini spacecrafts, scientists noticed that points of this hexagon rotate around its center at nearly the same rate that Saturn rotates on its axis.

They also noticed an Earth-like jet stream air current flowing eastward on Saturn at about 350 km/h, seemingly following along the rim of the hexagon.

But even though they have a pretty good idea what it is, they're not quite sure how this bizarre hexagon formed.

"Scientists have bandied about a number of explanations for the hexagon's origin," reports. "For instance, water swirling inside a bucket can generate whirlpools possessing holes with geometric shapes. However, there is of course no giant bucket on Saturn holding this gargantuan hexagon."

In this movie, taken by NASA's Cassini spacecraft, has been colourised to emphasise certain aspects of the hurricane. You can see this monstrous hurricane spin as a bunch of small vortices move around.

"The hexagon is just a current of air, and weather features out there that share similarities to this are notoriously turbulent and unstable," Andrew Ingersoll, a Cassini imaging team member, said in a NASA press release.

"A hurricane on Earth typically lasts a week, but this has been here for decades - and who knows - maybe centuries."

This article was originally published by Business Insider.

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