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Can We Call Pluto and Charon a 'Binary Planet' Yet? 115

astroengine writes The debate as to whether Pluto is a planet or a dwarf planet rumbles on, but in a new animation of the small world, one can't help but imagine another definition for Pluto. As NASA's New Horizons spacecraft continues its epic journey into the outer solar system, its Kuiper Belt target is becoming brighter and more defined. Seen through the mission's Long Range Reconnaissance Imager (LORRI) camera, this new set of observations clearly shows Pluto and its biggest moon Charon locked in a tight orbital dance separated by only 11,200 miles. (Compared with the Earth-moon orbital separation of around 240,000 miles, you can see how compact the Pluto-Charon system really is.) Both bodies are shown to be orbiting a common point — the "barycenter" is located well above Pluto's surface prompting a new debate on whether or not Pluto and Charon should be redefined as a "binary planet".
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Can We Call Pluto and Charon a 'Binary Planet' Yet?

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  • Admit it. (Score:4, Funny)

    by Anonymous Coward on Friday August 08, 2014 @06:13PM (#47634033)

    You're just trying to troll Neil Tyson for the hilarity that ensues.

    • by Anonymous Coward

      And xkcd, and a Psych movie if there ever is one. (You can't entirely hate a TV show where "You heard about Pluto?" is used as a pick-up line.)

    • Agreed. My first thought was that this article is just trying to bait Neil deGrasse Galactus into another fight.
  • by turkeydance ( 1266624 ) on Friday August 08, 2014 @06:13PM (#47634035)
    seriously....call Pluto what it is...ClickBait.
  • The debate as to whether Pluto is a planet or a dwarf planet rumbles

    What's with this "dwarf" nonsense — and big planetarism [slashdot.org]? We demand equal gravity for all planets [thepeoplescube.com]!

    • What's with this "dwarf" nonsense â" and big planetarism? We demand equal gravity for all planets!

      Why? We don't grant equal gravity to all arguments. Discrimination! :)

      I think we should grant equal comedy to all arguments. They everybody would "lighten up" and have a good time.

    • by Tablizer ( 95088 )

      But we need more trickle-down gravity until the sun bursts forth and spreads the wealth to the poor Kuiper ghettos, as the job creating nova the sun could be if not for the strangulating socialist regulation of the speed of light stuck at c.

  • by Henriok ( 6762 ) on Friday August 08, 2014 @06:27PM (#47634121)
    The arguments for demoting Pluto from its planetary status still holds. And hardly anyone objects to Pluto and Charon together as a binary system. But this "new" insight does not promote Pluto/Charon to planetary status. Binary dwarf planet, binary kuiper belt object, binary plutoid. Absolutely. Binary planet? No.
    • by jonfr ( 888673 ) on Friday August 08, 2014 @08:08PM (#47634895)

      Anything that is a sphere and orbits a star is a planet. Asteroids don't have sphere shape. Same goes for comets. The reason for the name "dwarf planets" is that of naming issue. There are more than 100 planet object out there, most of them smaller than planet Mercury.

      Haumea is a planet, but is minor elongated due it's rapid orbital period.

      http://en.wikipedia.org/wiki/H... [wikipedia.org]

      List of other dwarf planets.

      http://solarsystem.nasa.gov/pl... [nasa.gov]

      Then there is a chance of Earth size planets (both above and below in size and mass) in the outer region of our solar system that have not yet been discovered. At least there are clues about them today, even if they have so far not yet been found. It is my guess they are going to be found, given time and advances in technology that allows for better detection of outer orbital planets in our solar system.

      http://www.space.com/7728-eart... [space.com]
      http://www.theguardian.com/sci... [theguardian.com]

      There is a lot out there that we don't have no clue about and there are discoveries to be made (if the funding holds).

      • by Mal-2 ( 675116 )

        Anything that is a sphere and orbits a star is a planet. Asteroids don't have sphere shape. Same goes for comets.

        Ceres and Vesta are nearly spherical, yet are asteroids. Do they get counted as planets too? (They used to be.)

        You're right that the definition was tailored to keep the number of defined "planets" within reason. There was no way to include Pluto in this category and NOT include Eris, Haumea, Makemake, etc., so the definition was tailored to exclude them. It also happens to exclude Ceres and Vesta, though it wouldn't be a huge problem if they were considered planets (as they are the only two members of their

        • by Anonymous Coward

          Ceres is a dwarf planet. Same reasons as Pluto.

      • Sorry, but wrong. One of the qualifications to be named as a planet is that the object has cleared its orbit, something Pluto has not done.
        • by ihtoit ( 3393327 )

          neither has Jupiter. Zing.

          • by Urkki ( 668283 )

            neither has Jupiter. Zing.

            "Cleared its orbit" means, the planet controls everything which shares or crosses orbit with it. This may mean the usual moons, but also oribtal resonance (such as the Pluto-Neptune resonance) and minor bodies oribiting the Lagrange points of the planet (Trojans at L4/L5) instead of the planet itself like the usual moons.

      • by ihtoit ( 3393327 )

        I think the IAU new definition of a planet includes the condition that it has cleared its orbital track of any other significant debris. Pluto hasn't, it has at least seven satellites and there are many other unconnected bodies sharing the same orbit (last I heard at least twelve, of significant size, at various and seemingly random angular separations)... ironically, this would disqualify Jupiter as well, since it is preceded and followed in its orbit by two clouds of debris (Trojan asteroids) which are lo

  • Pluto is a Planet (Score:1, Insightful)

    by sexconker ( 1179573 )

    Pluto is a planet. The definition of a planet is arbitrary, and always will be.
    Trying to forcefully change the definition after it's already in use is fucking retarded and does nothing but cause confusion.

    For other instances of dipshits trying to hijack language and make it worse, see "non-flammable" and the dipshits who insist that a kilobyte is 1000 bytes.

    • There was no definition of planet, that was the point. Dictionary definitions don't count, because the dictionary definition would include asteroids, comets, the sun and moons. If you want those included in the planet category, go study Indo-European astrology.
    • Pluto is a planet. The definition of a planet is arbitrary, and always will be.

      What makes your arbitrary definition of "planet" - one that allows you to declare without qualification that it is a planet - better than the IAU's?

      Trying to forcefully change the definition after it's already in use is fucking retarded and does nothing but cause confusion.

      Not when the old definition is itself revealed to be "fucking retarded" (technical term, is that?) and causes more confusion once more data becomes available.

      see "non-flammable"

      Did you mean "inflammable"?

      and the dipshits who insist that a kilobyte is 1000 bytes.

      What, like the dipshits at the the International Organization for Standardization? Just because you don't like it, doesn't make everyone else unquestionably wrong.

      • I'm totally baffled about the "non-flammable" thing. I think sex_conker just likes being confused because the alternative is too difficult for him.

      • Pluto is a planet. The definition of a planet is arbitrary, and always will be.

        What makes your arbitrary definition of "planet" - one that allows you to declare without qualification that it is a planet - better than the IAU's?

        Trying to forcefully change the definition after it's already in use is fucking retarded and does nothing but cause confusion.

        Not when the old definition is itself revealed to be "fucking retarded" (technical term, is that?) and causes more confusion once more data becomes available.

        see "non-flammable"

        Did you mean "inflammable"?

        and the dipshits who insist that a kilobyte is 1000 bytes.

        What, like the dipshits at the the International Organization for Standardization? Just because you don't like it, doesn't make everyone else unquestionably wrong.

        My definition makes more sense and is better because it's ALREADY IN USE.
        You can't fucking change the meaning of a word willy-nilly, because that causes ambiguity. Does the speaker/author mean the new definition or the old one? When was this written? What was the more popular definition at the time?

        For inflammable, look up the fucking Latin roots inflammare and flamma.

        For kilobytes, again, the issue is about what was in use already and how changing shit adds ambiguity. Computer science has damn good rea

        • My definition makes more sense and is better because it's ALREADY IN USE.

          You mean the "blah blah blah and Pluto" definition? Because that was pretty much the definition for some time...

        • My definition makes more sense and is better because it's ALREADY IN USE.

          A definition is not automatically better simply because it's already in use (indoor voice, please). It certainly doesn't intrinsically make "more sense" because of that fact.

          In medieval times units of measurement were "defined" by lining up random churchgoers and measuring the combined length of their feet. Would you have resisted the introduction of a standardised measure [wikipedia.org] because the former was "already in use"?

          You can't change the meaning of a word willy-nilly, because that causes ambiguity.

          You're talking about the common usage of words. The IAU's problem was that their formal definiti

    • If you want to call Pluto a planet, you'll have to call Eris, Haumea, Makemake, Ceres, and a whole bunch of others planets too.

      Keep in mind that Ceres is spherical, orbits a star, and was known for 200 years but was NOT considered a planet during this time.

      Language can be arbitrary, sure. But why insist on it being self-contradictory?

      • And I would consider them planets.

        • They are dwarf planets. Not good enough for you? Do you have to lump every single non-asteroid object in the solar system in the same category?

          The purpose of language is to communicate ideas in an efficient way. There's a reason, for instance, that the most commonly-used words are the shortest ones, and that things that are semantically different are given different words.

          When using the word 'planet', it is far more likely that you have the 8 actual planets in mind, not Makemake or Haumea. So it makes sense

          • PS, I want to add that the IAU doesn't care what the average Joe calls them. Their definitions are for their own internal scientific usage. You can call them whatever you want. But if you want the proper term that actual astronomers use, it's "dwarf planet."

    • > Pluto is a planet. The definition of a planet is arbitrary, and always will be.

      If you can find an astronomy textbook from the 1830's or early 1840's, it'll list 11 planets...
      Mercury
      Venus
      Earth
      Mars
      Ceres (discovered 1801)
      Pallas (discovered 1802)
      Juno (discovered 1804)
      Vesta (discovered 1807)
      Jupiter
      Saturn
      Uranus (discovered 1781)

      As time went on, more and more asteroids were discovered. Today, there are a few hundred thousand asteroids. To keep the number of planets at a manageable number, the asteroids wwere

  • What debate? (Score:5, Informative)

    by glwtta ( 532858 ) on Friday August 08, 2014 @06:35PM (#47634193) Homepage
    Planet and Dwarf Planet are arbitrary labels defined by the IAU.

    How can you "debate" about that?
    • by khallow ( 566160 )
      The debate comes in that those arbitrary labels can be changed to other arbitrary labels.
      • by glwtta ( 532858 )
        That's what 'arbitrary' means.
        • I know! It's the best kind of debate: having no substantial meaning at all, it can last forever as an excuse for people to insult and trump one another. It's a perfect Slashdot article; we need more of these.

    • by Urkki ( 668283 )

      Planet and Dwarf Planet are arbitrary labels defined by the IAU.
      How can you "debate" about that?

      Well, they're not really arbitrary. There are at least three points you can argue about:

      1. Argue to change the definition (actual written words), which determines which is which and what isn't either.

      2. Argue about interpretation of the defintion. Though, if this succeeds, then it makes the definition ambiguous, and the classification of border cases does become arbitrary.

      3. Argue about the chosen terms "planet" and "dwarf planet". For example I'm personally not too happy having "dwarf planets" which are no

  • by glwtta ( 532858 ) on Friday August 08, 2014 @06:42PM (#47634225) Homepage

    This mission will put a new spotlight on Pluto and its âoedwarf planetâ status, potentially highlighting its current classification as a woefully inadequate description of such a dynamic and interesting binary system.

    Ok, so it's a "binary dwarf planet" - can we tone down the prose now?

  • The barycenter of the Sun and Jupiter is above the surface of the sun, does that mean we'd have to reclassify our solar system as a binary star system now? http://spaceplace.nasa.gov/bar... [nasa.gov]
    • Re: (Score:2, Troll)

      by jklovanc ( 1603149 )

      No, because Jupiter is not a star. It is the same reason that Pluto/Charon is not a binary planet as neither of them is a planet.

  • by Anonymous Coward

    Unless Pluto (and Charon) shifted orbit into the planetary plane, nothing has changed and any desire to call it a planet is just sentimentality.

  • Pluto doesn't care what you call it. It's going to be around when you are dust in the wind. Oh and I don't care either.
  • what is that? Why not furlongs or Manhattans?
  • No phone lines yet. Sorry.

  • I suppor tthe right of the people of Pluto to decide their own destiny, and not be ruled by any arbitrary group of people on some other planet.
    Freedom for the Plutocrats

  • Uh, folks, Pluto actually has FOUR moons... Charon: Discovered in 1978, this small moon is almost half the size of Pluto. ... Nix and Hydra: These small moons were found in 2005 by a Hubble Space Telescope team studying the Pluto system. Kerberos: Discovered in 2011, this tiny moon is located between the orbits of Nix and Hydra. ...and it just keeps on thumbing it nose at the dwarfists, and now, the binarists. But tell me, how is a FIVE body system a BINARY system? Hmmmmm?
    • OOOps! (Score:4, Informative)

      by Unknown74 ( 3041957 ) on Friday August 08, 2014 @11:05PM (#47635553)
      My mistake...Pluto has FIVE moons. Charon: Discovered in 1978, this small moon is almost half the size of Pluto. It is so big Pluto and Charon are sometimes referred to as a double planet system. Nix and Hydra: These small moons were found in 2005 by a Hubble Space Telescope team studying the Pluto system. Kerberos: Discovered in 2011, this tiny moon is located between the orbits of Nix and Hydra. Styx: Discovered in 2012, this little moon was found by a team of scientists search for potential hazards to the New Horizons spacecraft flyby in 2015. may the 'little planet that could' keep right on thumbing it nose at everybody!
      • Re: (Score:2, Funny)

        by Anonymous Coward

        Among the moons of Pluto are... wait, I'll come in again.

  • We've known for at least a decade now that Pluto/Charon's barycenter is outside the mass of Pluto. That was one of many arguments used to delist Pluto from the Solar System planets. Those same "Pluto is a planet" fossils probably would demand Ceres be restored to planetary status, if they lived two hundred years ago.

One man's constant is another man's variable. -- A.J. Perlis

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