(CNN)In 1610, after he built his telescope, Galileo Galilei first spotted enormous Saturn's gigantic rings. More than 400 years later, astronomers have in a sense dwarfed that discovery with a similar first. Using powerful optics, they have found a much larger planet-like body, J1407b, with rings 200 times the size of Saturn's, U.S. and Dutch astronomers said. It lies some 400 light-years away from Earth. For decades, scientists have believed that many moons around large planets formed out of such ring systems. But this is the first one astronomers have observed aside from Saturn's, they said. It was discovered in...