Why is Pluto not considered a planet because it’s too small, but some planets are made entirely of gas and considered planets?

Question

Edit: I know I sound like an idiot in the replies, but I’m really asking genuine questions so thank you all for being patient and answering

In: Physics

Answer 1

Because it being small isn’t itself disqualifying it from being a planet. All planets also have to have a clear orbit, where other large bodies do not regularly pass. Pluto doesn’t have that, and so in 2006, it got redesignated as a dwarf planet. It’s okay for it not to be a planet.

If we allowed it to be one, we’d also have to add Eris, Haumea, Makemake, Gonggong, and Quaoar, as well as many others. It’s much better to make a different classification for these other objects, aka, dwarf planets