Saturn's rings sure are pretty, and Matt Damon’s been to Mars, but our eight-planet solar system may not be that special after all. Today, scientists using data from NASA’s Kepler spacecraft announced they’d discovered an eighth planet orbiting a star 2,500 light years away. They’ve named the planet Kepler-90i after the star it orbits, Kepler-90, which is slightly hotter and more massive than our sun.