Pluto: not a planet

A lot of folks were upset and confused when Pluto was demoted from it's planetary status a few years ago. This video makes a nice comparison of Pluto's demotion with Ceres, which was also a planet for a while in the 1800s until astronomers found many more small bodies in nearby orbits, eventually calling the whole bunch of them asteroids. Same story with Pluto. Astronomers discovered many more Kuiper belt objects out there beyond Neptune, including one that's bigger than Pluto (Eris).

The New Horizons spacecraft is on its way to Pluto to break the bad news.



Plus, Pluto is really small.