Our Solar System is a pretty busy place. There are millions of objects moving around – everything from planets, to moons, to comets, and asteroids. And each year we're discovering more and more objects (usually small asteroids or speedy comets) that call the Solar System home. Astronomers had found all eight of the main planets by 1846. But that doesn't stop us from looking for more. In the past 100 years, we've found smaller distant bodies we call dwarf planets, which is what we now classify Pluto as. The discovery of some of these dwarf planets has given us reason...