Astronomers knew there was something odd going on when they looked for Uranus' newly discovered outer rings. For starters, they could only find one. After months of analysis, they figured out why: Unlike its red partner, the missing ring is so blue, it fell outside the telescope's range. "It's funny that this research got started by something we didn't see," said Imke de Pater, with the University of California at Berkeley and lead author of a paper describing the discovery in this week's journal Science. The initial discovery of a pair of outer rings circling Uranus was made by astronomers...