The definition of a planet has been debated for hundreds of years. It has changed based on what scientists know and what they want to study. The International Astronomical Union recently voted on a new definition that fit Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune - but not Pluto.

Take a look at the three parts of the new definition and vote on which you would keep.

Discover if Pluto is part of your Planetary System!