Question

Pluto has a shape that is nearly round,and it orbits the sun,it has five known moons.why is it called a dwarf planet and not a planet?

Answer 1

There are three things needed to be classified as a planet.

Pluto meets 2 of the 3.

The one it does not meet is it doesn’t “clear the neighborhood” which means a planet needs to be gravitationally dominant over all objects around it. Meaning smaller bodies ( asteroids) would either combine with the larger body making it bigger or pushing them away ( out of their orbit) so they do not collide with the larger body.