On Monday, NASA released stunning photos and video of a massive storm that researchers believe has been swirling at high speed around Saturn's north pole for years.
Called a "Saturn hurricane," the huge vortex was first detected when the Cassini-Huygens spacecraft entered orbit around the planet in 2004, NASA said.
Cassini -- an unmanned probe funded by NASA, the European Space Agency, and the Italian Space Agency -- had to wait years for Saturn's north pole to be lit up by the sun before it could photograph the storm, NASA said. The spacecraft also had to change its orbit to get a clear view of the area, a process that required years of planning.
Now that researchers have taken a closer look, they're able to better estimate vortex's size -- and it's truly colossal. Its eye alone is about 1,250 miles across (about 20 times larger than an average hurricane on Earth), and clouds on the storm's outer edge are churning at about 300 mph.
Though NASA's statement Monday said the agency hopes to study the Saturn hurricane to learn more about hurricanes on Earth, the storm differs from terrestrial hurricanes in one major way: there's no ocean beneath it.
"That's one of the puzzles we're trying to figure out," Cassini imaging team member Andy Ingersoll said.
In addition, the Saturn hurricane is locked in one place.
It took scientists from 18 countries more than 20 years (and more than $3 billion). Cassini was launched from Cape Canaveral in 1997 with the goal of learning more about the mysterious planet and its storms.
Click the video above to watch the hurricane-like storm in action.