NASA’s Hubble Tracks New Decagon Encircling Saturn’s South Pole

Recent observations with NASA’s Hubble Space Telescope have revealed a giant, evolving, 10-sided atmospheric wave encircling Saturn's south pole. 

"Megastorm" effects on Saturn last centuries

Megastorms occur approximately every 20 to 30 years on Saturn and are similar to hurricanes on Earth, although significantly larger. But unlike Earth’s hurricanes, no one knows what causes megastorms in Saturn’s atmosphere.