• Echo Dot@feddit.ukEnglish
    41·
    12 days ago

    People don’t like that definition of planet because it’s terrible. Which is my point about the last criteria. If in order for it to be considered a planet it has to have absorbed the majority of all material then double planets can’t be planets, because they haven’t.

    What about a planet that also has a large mass at its L3 point, can either of those objects be a planet if the other object also exists?

    If a planet gets ejected from its star system, what is it now, a very large asteroid?

    This definition of planet is problematic because it’s transitory and largely relies on factors that don’t have material effects on the object. Spherical objects can form in interstellar space, a star is not required. We just think that planets tend to form around stars because they’re easier to see in that scenario.

    • Tiresia@slrpnk.netEnglish
      31·
      12 days ago

      “Planet” is about an astronomic object’s relation to other objects. That’s why it’s called a planet - a wanderer. If you want a convenient term for spherical astronomic bodies that aren’t stars, white dwarfs, black dwarfs, brown dwarfs, neutron stars, black holes, or tennis balls shot from a spaceship’s airlock, invent your own. It’s a free language.

      That said, I don’t think you understand what a majority is, since it answers or contradicts half your remarks. A double planet might have one planet and a moon or two dwarf planets. A planet may have a dwarf planet in its L3 point. A planet ejected from a star system becomes a rogue planet.

      Dwarf planets, rogue planets, double planets, and planetoids all aren’t planets.