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[–] 1 point 1 hour ago (2 children)

What's the "purest sense of the term"? A planet is presently defined as a body which orbits a star, has enough mass to be roughly round, and has cleared its orbit of other objects. Dwarf planets are defined as fulfilling the first two criteria, but not the third.

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  • [–] 1 point 1 hour ago (1 child)

    I mean that these descriptions are somewhat arbitrary. Roughly round is not a very precise delineation, there will be edge cases where it’s not clear which category they fall into

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  • Roughly round is not a very precise delineation

    The actual qualification is "hydrostatic equilibrium", but I didn't want to complicate the point with technical mathematical jargon.

    there will be edge cases where it’s not clear which category they fall into

    Which is pretty par for the course so far as scientific classifications go. Classification is a human endeavor to attempt to neatly categorize things to better understand them, but the universe is what it is and defies tidy categorization. Just about any scientific classification you can devise will have edge cases and ambiguity.

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