Feast your eyes on one of the most puzzling planetary mysteries our solar system has to offer. In this photograph of Saturn's north pole, captured by NASA's Cassini spacecraft in 2009, clouds can be seen encircling the planet at about 77 degrees north latitude. Even at such a high parallel, the massive six-sided jet stream has a diameter more than twice that of Earth's.
How did such a cloud system form, and where did it acquire the energy to do so? These are the kinds of questions scientists investigating the planet's perplexing hexagon are faced with — but one of the biggest questions of all is how the system has managed to retain its surprisingly symmetrical shape for so long, even while whipping around the planet at upwards of 200 miles per hour.
"The longevity of the hexagon makes this something special, given that weather on Earth lasts on the order of weeks," explains Kunio Sayanagi, a Cassini imaging team associate at Cal Tech [this curious cloud pattern was first observed by NASA's Voyager spacecraft over thirty years ago]. "It's a mystery on par with the strange weather conditions that give rise to the long-lived Great Red Spot of Jupiter."