The image: Scientists have known about Saturn's recurring "Great White Spot" since it was first observed, in 1876. But only this year has the famous storm been photographed in "unprecedented detail," by NASA's Cassini spacecraft. (See a photo below.) Unlike Jupiter's Great Red Spot, which is a constant feature of our solar system's largest planet, Saturn's storm usually only shows up every 30 years. And this time around, it's "the most intense storm ever seen on the ringed planet." The spot is a storm of churning ammonia and water that packs as much energy as Earth receives from the sun in a whole year. It's casting out loud radio noise and "almost continuous lightning discharges." At about 6,200 miles wide, the storm nearly matches the width of the Earth, and its tail wraps around Saturn completely. 

The reaction: This is "one bad mutha shut-yo-mouth of a thunderboomer," says Geoff Brumfiel at Imagine the lightning that must be "dancing prodigiously beneath those clouds," says Phil Plait at Bad Astronomy. The raw power of this storm, and the fact that it's roughly the size of Earth, is "amazing to ponder." Now the challenge will be predicting when the next storm will appear, says Professor Peter Read of Oxford University, as quoted by Britain's Telegraph. But there's no denying that these are "some of the most detailed observations so far of such a dramatic event." See the storm for yourself: