Pluto's classification as a planet has had a history of changes. Since 2006, per the International Astronomical Union's planetary criteria, Pluto isn't considered a planet because it hasn't cleared the neighborhood around its orbit of other objects.
Pluto's classification as a planet has had a history of changes. Since 2006, per the International Astronomical Union's planetary criteria, Pluto isn't considered a planet because it hasn't cleared the neighborhood around its orbit of other objects.