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Our Moon Could Become a Planet

Posted by ryuzaki0 on from the size-does-matter dept.

anthemaniac writes "Earth's moon is drifting away from us more than an inch every year. In a few billion years, if the system survives, the moon would be reclassified as a planet under the new IAU definition. You gotta wonder if the astronomers who dreamed this definition up had thought of that."

24 of 438 comments (clear)

  1. So what? by brunes69 · · Score: 1, Insightful

    OF COURSE it would. It would no longer orbit the earth, so it would no longer be a moon.

    This smacks of an elementary-level understanding, I don't know why it made the front page. If you change the physical properties of a named object, and want to name it something else, who cares?

    1. Re:So what? by Fyz · · Score: 5, Insightful

      If you'd bothered to RTFA, you'd find that the moon would be reclassified as a planet when the systems center of gravity no longer resides inside the Earth.

      I would gladly send my kid to this elementary school if they could prove that they could teach concepts like orbital decay and barycenters to to nine-year-olds.

    2. Re:So what? by Mr2cents · · Score: 4, Insightful

      I already consider the moon-earth as a bi-planetary system. What's the big deal with these definitions, anyway? No matter where you draw the line, there will always be cases where there will be discussion. Like the criterium that the object has to be "nealy spherical" because of it's own gravity. Lots of planetoids are somewhere on this vague border.

      Comets, asteroids, planets, stars, they all have grey areas between them.

      --
      "It's too bad that stupidity isn't painful." - Anton LaVey
    3. Re:So what? by hplasm · · Score: 0, Insightful
      Comets, asteroids, planets, stars, they all have grey areas between them.

      Space is grey now?

      --
      ...and he grinned, like a fox eating shit out of a wire brush.
    4. Re:So what? by Anonymous Coward · · Score: 1, Insightful

      The problem that I foresee having the moon drift further away from the earth is missing the gravitational forces that we depend on. The earth's axis would not stay constant plus the tides would not circulate the oceans. The moon keeps our planet habitable.

    5. Re:So what? by Digz · · Score: 2, Insightful
      ..asteroids.. they all have grey areas between them.

      Assuming you're playing the 2600 version, you might want to get your TV checked. The area between the Asteroids should be black.

      Oh, and be careful with pulling down to warp. It can throw you into the darndest areas.

      ;)

      --
      SYS 64738
  2. Re:Got enough time to change the definition by Flibz · · Score: 3, Insightful

    Plus the human race will have rendered the Earth uninhabitable by then so there'll be nobody to care...

  3. Hmm by Klaidas · · Score: 3, Insightful

    No-one knows if the humans will survive that long, maybe there will be no-one to rename it.

    1. Re:Hmm by kalirion · · Score: 4, Insightful

      No-one knows if the humans will survive that long, maybe there will be no-one to rename it.

      A billion years? If our descendents exist by that time, they won't be considered human by our current definitions. I think it's a safe bet that the only way humans as we know them today could survive that long would be by either time-traveling or becoming a part of some aliens' (or dolphins') "Save the Humans" project.

  4. Many things will happen ... by Ihlosi · · Score: 3, Insightful
    ... when hell freezes over.



    In a few billion years, if the system survives,



    If we manage to figure out a way to move Earth away from the sun before it goes red giant, it will most likely involve leaving any unnecessary baggage (like orbiting balls of rock) behind.

  5. Re:This is going to complicate things. by terevos · · Score: 5, Insightful
    I may be woefully ignornant on the subjecct but I really don't see why sticking with the current definition is a problem.


    Could you tell me what the 'current' definition is?

    The problem was that there wasn't a definition before. More of just an accepted method of measurement. And it was arbitrary. I think it was generally based off of 'anything as big or bigger than pluto is a planet'. That's not scientific at all. The new definition is great. It relies on science to determine the status of 'planet' rather than something arbitrary picked out of the sky to satisfy what people had learned in grade school.
  6. Re:ok by Flibz · · Score: 1, Insightful

    I was going to attempt to mutter something vaguely amusing about the Earth being/not being the centre of the universe.

    But I can't be bothered.

    So there. :P

  7. Few Billion Years? by the_crowing · · Score: 5, Insightful

    I really don't think humans will last another thousand years (with the way we're poluting the environment and declaring war on each other plus the rising threat of nuclear weapons) let alone another few billion years. And provided we do last that long, I'm sure the standards for classifying planets will have changed hundreds of more times by then.

  8. Re:This is going to complicate things. by gklinger · · Score: 3, Insightful

    Heretofore a planet was (loosely) defined as a large mass in orbit around a star. In our solar system the primary tenet of planethood was that the object orbited the Sun rather than orbiting a body which orbited the Sun. There are other conditions, of course, because not everything that orbits the Sun is a planet but it's a good place to start. Simply put though, if an object doesn't meet the criteria of a) orbiting the sun and b) being of a certain size or larger it doesn't make the cut. If the IAU dispenses with or at least loosens those two historical criteria the solar system will suddenly be filled with planets and confusion (at least amongst the non-astronomer crowd) will ensue. That's the real problem. I think there is more to think about than simple semantics.

  9. Re:And what's the problem? by jolyonr · · Score: 4, Insightful

    Please stop giving +1 Insightfuls to people who either a) haven't read the article or b) haven't undestood it. The moon could be reclassified as a planet EVEN IF IT STILL ORBITS THE EARTH. It depends on whether the center of gravity of the pair is inside the earth or not.

    --


    Please read my Canon EOS tech blog at http://www.everyothershot.com
  10. Re:moon... by Flibz · · Score: 2, Insightful

    I'll still be a human. A dead human, but a human nonetheless...

    Unless I get reincarnated. In which case I'll be a three toed sloth. Or a dung beetle. Or... Or... So many karmic possibilities, so few incarnations!

  11. Re:This is going to complicate things. by Flibz · · Score: 3, Insightful

    Unless of course he happens to be an oyster or something...

    http://en.wikipedia.org/wiki/Egg_(biology)

  12. Re:Gosh. How shocking. by MindStalker · · Score: 4, Insightful

    This is called a Twin Planet. And no it would nolonger orbit the earth the earth, the "moon" would orbit eachother at a common point. Either way, I see no reason that once we have this designation of moon vs planet why we should be so beholden of "our" moon that we can't accept it nolonger being a moon. We shouldn't change the definition just to fit some popular idea.

  13. Earth won't still be rotating by then by codemaster2b · · Score: 4, Insightful

    A few billion years? Why should they care?

    It was projected that in a matter of millions of years, the moon will cause the earth to stop rotating altogether. Without rotation, do you seriously think we will inhabit this planet?

    For that matter, in a matter of millions of years, we should have developed a technology for making the earth rotate as fast as we wish, and moving the moon back where we want it to be. All it requires is enough rocket-power by even today's standards.

    --
    And over there we have the labyrinth guards. One always lies, one always tells the truth, and one stabs people who ask t
  14. Who cares? by porkchop_d_clown · · Score: 2, Insightful

    Obviously, people care tremendously, which is why we ended up with this half-assed bandaid of a definition - which is an attempt to use a single word to describe three wildly divergent phenomena in a way that makes scientific sense and will pass muster with every pseudoscientist who thinks they have a right to an opinion on the matter.

    The brutal truth is that there are at least three types of bodies that orbit the sun - rocky planets, gas giants, and bodies made up primarily of ices like Pluto and his friends. Lumping them together as a single thing is stupid; excluding bodies like Titan, Ganymeade and Europa from their "club" also makes little sense - but imagine bruhaha that would happen if astronomers simply stopped talking about moons and planets and started talking about rocks, gasballs and iceballs...

    --
    Clear, Dark Skies
  15. Planetary System rather than Planet/Moon by scruffy · · Score: 3, Insightful
    I'd prefer to think of the Earth and the Moon as a single planetary system, consisting of two planets (both easily satisfying the big enough/round enough definition). For simplicity and consistency, we can call the system Earth just like old times.

    Ditto for Pluto and Charon.

  16. Re:Gosh. How shocking. by frankie · · Score: 2, Insightful

    Wrong, wrong, wrong! Just RTFPP. The moon does not have to completely escape the Earth's gravitational pull in order for Porkchop's comment to apply.

    The terms "moon" and "double planet" are arbitrary human-made definitions. And they have a generally recognized boundary: is the barycenter inside the larger object or not? FYI, the Earth-Moon system is 79% of the way there.

    Obviously, the moderators who gave a +3 Insightful to your comment mistook your arrogant tone for expertise.

  17. Re:A Species lasts ... by Anonymous Coward · · Score: 1, Insightful

    It would take more than humans to destroy all species on Earth. Granted, it would be a huge setback for the complexity of life, but plenty of life would survive a war which would kill all humans.

  18. Re:In a few billion years... by advocate_one · · Score: 2, Insightful
    What's the estimated surface tempurature of this reloaced Earth? How big would the sun look from there?

    'kin hot and 'kin huge... how about most of the sky??? it expands out to 99% of 1 AU and we move out to 1.7 AU...

    I'm not sure about some of the young whippersnappers in here... but I, for one, certainly don't expect to be around to find out...

    --
    Donald 'Duck' Dunn: We had a band powerful enough to turn goat piss into gasoline.