Question

Why was Pluto discredited as a planet?

Answer 1

Pluto discredited as a planet beacuse pluto have no 100% Specialty of Planet

Answer 2

in 2006, International astronomical union made a definition for a planet.

1 It should be going round s star.

2 It should have enough mass to form a sphere by gravity.

3 It must clear objects in neighborhood

The third condition pluto was not obeying as it crosses Neptune orbit.So,it was graded as dwarf planet...