Hubble discovers a mysterious dark spot on Neptune, and it's getting bigger

The mighty Jupiter gets a lot of attention for its constantly-shifting face, but it's not the only planet in our solar system with some serious personality. Neptune, the large frozen ball of methane and various other frigid gasses sitting way out in the outer reaches of our system, is surprisingly active, and the Hubble Space Telescope just caught it doing something nobody had ever seen before. Astronomers have known for a long time that Neptune's surface occasionally becomes dotted with dark sp...