I mean, there are literal flat-earthers out there… But for anyone curious about why Pluto is no longer classified as a planet - and what its size has to do with it - Pluto is now considered a dwarf planet because, while it’s large enough to be spherical, it isn’t big enough to dominate its orbit and clear out other objects in its path.
That’s correct by definition, but the reason the definition was changed to exclude pluto was because our knowledge changed.
We found more Pluto-like objects and it became clear they weren’t the same thing as the other 8 planets. They needed their own classification. So we created one (Dwarf Planets) and put Pluto in it along with its brethren.
I mean, there are literal flat-earthers out there… But for anyone curious about why Pluto is no longer classified as a planet - and what its size has to do with it - Pluto is now considered a dwarf planet because, while it’s large enough to be spherical, it isn’t big enough to dominate its orbit and clear out other objects in its path.
And also because if we included Pluto, we’d have to include another half dozen Pluto-sized dwarves we’ve discovered since.
But, yeah, my understanding is that it’s really about dominance. Pluto is too submissive. Not alpha enough, if you will.
That’s correct by definition, but the reason the definition was changed to exclude pluto was because our knowledge changed.
We found more Pluto-like objects and it became clear they weren’t the same thing as the other 8 planets. They needed their own classification. So we created one (Dwarf Planets) and put Pluto in it along with its brethren.