The IAU denied Pluto its planet designation because it was discovered by an American using an American telescope and modern calculations. `Now, that was back when Bush was president - it was really a protest against the Iraq Wars - but today, they will come up with some other excuse.
The thing is more of a planet than Mercury. Has bigger moons than Mars.
“According to the team, the definition of a planet should be based on its intrinsic properties, rather than ones that can change, such as the dynamics of a planet’s orbit.”
This is especially true in the case of “rouge planets”. Planets that form in a solar system but then somehow get kicked out, possibly by the gravitational pull of a passing star.
The spherical criterion strikes me as arbitrary...earth is not a perfect sphere; eccentricity is what, 1/300?
Is the fact that Pluto crosses Neptune’s orbit relevant?
Again, Pluto is still a planet, just not a major planet.
The current list of dwarf planets is:
The five dwarf planets:
Ceres as seen from the Dawn spacecraft. It is the only dwarf planet in the asteroid belt.
Pluto as viewed by New Horizons space probe on July 13, 2015.
Eris and its moon Dysnomia viewed by the Hubble Space Telescope.
Makemake and its moon S/2015 (136472) 1 viewed by the Hubble Space Telescope.
NASA artist’s impression of Haumea.