Nothing like the hexagon has ever been seen on any other world. The structure, which contains a churning storm at its center, is about 20,000 miles (32,000 kilometers) wide, and thermal images show that it reaches roughly 60 miles (100 km) down into Saturn's atmosphere.

Scientists have bandied about a number of explanations for the hexagon's origin. 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.

Voyager and Cassini did identify many features of this strange hexagon that could help explain how it formed. For example, the points of the hexagon rotate around its center at almost exactly the same rate Saturn rotates on its axis. Moreover, a jet stream air current, much like the ones seen on Earth, flows eastward at up to about 220 mph (360 km/h) on Saturn, on a path that appears to follow the hexagon's outline.

Now researchers have developed a model they suggest matches the hexagon's features better than previous attempts.

"With a very simple model, we have been able to match many of the observed properties of the hexagon," study lead author Raúl Morales-Juberías, a planetary scientist at the New Mexico Institute of Mining and Technology, told Space.com.