why Isn't Pluto a planet ? :Pluto Isn't a planet because it does not meet the same criteria that the other planets need to be a planet there for Pluto is a dwarf planet . what are the three criteria that a planet needs to be a planet?
It must be big enough that its gravity has cleared away any other objects of a similar size near its orbit around the Sun
It must be big enough to have enough gravity to force it into a spherical,shape it must orbit the sun
I found this on ... NASA Science !!!!!!!!!!!!!!!!!