Book 8, Question 66
Why Is Pluto Now Called a Dwarf Planet?
Pluto is called a dwarf planet because astronomers refined what the word planet means! Pluto orbits the Sun and is round, but it hasn't cleared other objects out of its path. It's still a world, just in a new category.
More fun facts
- Pluto was thought of as our ninth planet for a long time.
- Pluto orbits in the Kuiper Belt, a disc-shaped zone of icy objects beyond Neptune.
- After astronomers found similar worlds deeper in the Kuiper Belt, Pluto was reclassified as a dwarf planet in 2006.
- The decision was made by the International Astronomical Union, a group of astronomers from around the world.
- Other dwarf planets include Ceres, Makemake, Haumea and Eris.
Sources: NASA Science, NASA Space Place, NASA Science
Questions kids ask
Which other worlds are dwarf planets?
Ceres, Makemake, Haumea and Eris are dwarf planets too.