- is Pluto really a planet?

Discussion in 'science, nature and environment' started by maya, Aug 16, 2006.

  1. maya

    maya timewasting fool (in every universe)

    must admit i very rarely participate in any discussions in this forum since i'm completely ignorant on the subject(s), but out of interest/curiosity the question must be asked:

    ...is Pluto really a planet? :confused:

    since the discovery of the new and (it seems) far more glorious Xena, err "Xenu"(sp?), also dubbed "the tenth planet" or "object number...something" , it seems like our poor old ninth planet pal has got even the most well-esteemed scientists turning the cold shoulder...

    sacrilegous whispers among those who usually (should) know these things say "pluto might just be an asteroid"...and, "if pluto had been discovered yesterday, it probably wouldn't have been classified as a planet"...

    ...are they right, or is everything relative and it's really a bit of both?

    or is this what the tabloids would label a "scientific hot potato"? oo-err :eek:

    the crowds have opinions, the wise ones too, let's hear them!
    i'm intrigued...
    Pickman's model likes this.
  2. Bob_the_lost

    Bob_the_lost Elsewhere

  3. Badgers

    Badgers Mr Big Shrimp!

  4. Enviro

    Enviro Make your assessment

  5. littlebabyjesus

    littlebabyjesus one of Maxwell's demons

    Definition officially is a spherical celestial object that has cleared its orbit around the Sun of debris. Pluto was judged not to have done that second bit sufficiently to qualify. It clearly still rankles 12 years later. The 'dwarf planet' categorisation places it alongside the likes of Eris, which is just as big as Pluto. If Pluto's a planet then so is Eris, I would have thought.

    One thing that counts against Pluto as a true planet is that it is so far off the ecliptic in its orbit.

    PursuedByBears and Badgers like this.
  6. Yossarian

    Yossarian free shrugs

    It's probably not really a planet, in the same way that Europe's not really a continent, but like Europe, maybe it should be kept in the group out of tradition. Not sure about declaring all the other Kuiper Belt contenders to be planets though, especially if it's going to mean I might be expected to have to spell "Quaoar."

    Badgers and littlebabyjesus like this.
  7. littlebabyjesus

    littlebabyjesus one of Maxwell's demons

    'Quaoar' and 'Makemake'. Really, astronomers are not to be trusted with naming things.
    Yossarian and Badgers like this.
  8. Crispy

    Crispy The following psytrance is baṉned: All

    Creator Gods of SoCAl Native Americans and Easter Island respectively. Haumea is the Hawaiian goddess of birth.
    Same guy (Michael Brown) on the team that discovered most of these objects, so you can probably blame him specifically. He also lead the campaign to demote Pluto.

    He's currently hunting down Planet 9, a "super earth" way out beyond Neptune. They have the orbit almost exactly nailed down now, but no idea of where along that orbit it is. With an orbital period of 15,000 years and very little sunlight shining on it, it will be very very hard to find. Almost certainly there though.

    NoXion likes this.
  9. cheesethief

    cheesethief Well-Known Member

    It's clearly not a planet if there's comparably sized things whizzing around in the solar system on independent orbits that we refuse to recognise as planets. Either they're all planets or none of them are. Personally I'm quite happy with the dwarf planet designation, because it allows lots of other minor bodies to come under the "sort of planet" moniker. They're not just big rocks, they're a type of fun sized planet.

    What I'd like to know though, is where's the line between dwarf planet and big rock? :hmm:
    NoXion likes this.
  10. littlebabyjesus

    littlebabyjesus one of Maxwell's demons

    Being roughly spherical? There's a critical mass above which an object's gravity will make it spherical.
    SpookyFrank and Badgers like this.
  11. cheesethief

    cheesethief Well-Known Member

    Presumably this is also dependent on density. Which implies some interesting theoretical possibilities - could a body that was mostly water be much smaller yet still qualify as a dwarf planet, on the basis that its lower density may allow it to spherically deform sooner than a rocky counterpart?

    And stretching the bounds of credibility to their extreme - could a rubble pile of diamond debris (the cores of two, small long dead stars in a close binary orbit end up colliding, smashing off huge chunks of each other into orbit, something improbable like that maybe...) form that was gravitationally bound, much larger than any conventional notion of a "rock", maybe into dwarf planet territory, but still have sufficient internal strength to resist being spherically deformed?
  12. NoXion

    NoXion Keep an eye out for diamonds

  13. SpookyFrank

    SpookyFrank If it's alive, don't lick it.

    A planet-sized ball of water would be considerably more dense than a gas giant like Jupiter.
  14. Crispy

    Crispy The following psytrance is baṉned: All

    Also, if warm enough to be water, it would evaporate. Plenty of water planetoids in our system, they're just ice, not liquid water.
    Badgers likes this.

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