The problem is if you include all the dwarf planets the list more than doubles and really you should include most of the moons too, Pluto is the biggest dwarf planet and it’s like, 1/3rd the size of our moon and 1/6th the mass. It’s really really tiny.
Eris is the most massive and initially thought to be the largest too, but now it’s known to be slightly smaller than Pluto. It was discovered in 2005, it initially appearing bigger than Pluto, plus the discovery of many similar, smaller objects nearby is what prompted the discussion of reclassification.
The universe is messy and any definition is going to encounter edge cases: planet-or-star edge cases became “brown dwarfs” and now there are also “sub-brown dwarfs” for its edge cases.
The problem is if you include all the dwarf planets the list more than doubles and really you should include most of the moons too, Pluto is the biggest dwarf planet and it’s like, 1/3rd the size of our moon and 1/6th the mass. It’s really really tiny.
Eris is the most massive and initially thought to be the largest too, but now it’s known to be slightly smaller than Pluto. It was discovered in 2005, it initially appearing bigger than Pluto, plus the discovery of many similar, smaller objects nearby is what prompted the discussion of reclassification.
The universe is messy and any definition is going to encounter edge cases: planet-or-star edge cases became “brown dwarfs” and now there are also “sub-brown dwarfs” for its edge cases.