Why is Pluto not a planet anymore?
Pluto's New League
Why is Pluto not a planet anymore?
For 76 years, Pluto was the solar system's ninth planet — a tiny ice world at the edge of everything, beloved by schoolkids everywhere. Then, in 2006, astronomers held a vote and kicked it out of the planet club. What happened?
The trouble started when astronomers found more ice worlds out past Neptune, in a region called the Kuiper Belt. Some were almost as big as Pluto. One, called Eris, might even be heavier. If Pluto was a planet, what about them?
