Also must be in hydrostatic equilibrium. There's very few objects that meet both above criteria and not this one, but there are a couple questionable ones.cmdraftbrn wrote:Hevach wrote:To be fair to the guy, there's a small number of actual, real scientists who do consider the moon a planet, because the Sun's gravitational effect on it is greater than Earth's, something that's only true of one other satellite in the solar system, Charon. There's no formal definition of double planet yet, though, because you need an actual group of objects to create a new classification and not just unusual examples of something else.
Not that I believe for a second he knows enough about the minutia of astronomical classification to know that anymore than an idiot who falls down the stairs and lands on a dictionary knows what antidisestablishmentarianism means.
the only accepted planet classification qualifiers that i know is
1. does it orbit the sun without orbiting another celestial body
2. does it clear its orbital path of spacial debris.
However, there's an undefined class of planet that the IAU discussed during the Pluto debate but never established criteria for: Double planet. After it was decided Pluto had to be reclassified (largely because of the "8 planets or 53" problem) it went through a few variations before they settled where they did. The possibility of creating a double planet classification that would elevate Pluto out of the dwarf class was considered - every variation on it ended up breaking some IAU rule (particularly about creating an entire classification with only one object to put in it), but some of them did weird things - one actually threw Jupiter's planetary status into question and another would have moved Earth and the moon to double planet classification.
The whole thing got dropped as more messy and arbitrary than one little ball of ice was worth, but just like Pluto's status getting shelved repeatedly until we started discovering dozens of similar objects, new discoveries could raise it again, and there's no telling which side Earth will end up on.