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Strange New 'Twin' Worlds Found 239

toomanyairmiles writes "The BBC reports on the the discovery of 'twin worlds' which orbit each other, successfully blurring the line between planets and stars. 'Their existence challenges current theories about the formation of planets and stars.' according to the Journal of Science article which reports their existence. 'The pair belongs to what some astronomers believe is a new class of planet-like objects floating through space; so-called planetary mass objects, or "planemos", which are not bound to stars.'"
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Strange New 'Twin' Worlds Found

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  • by nebaz ( 453974 ) * on Friday August 04, 2006 @01:29PM (#15847532)
    However insular we want to be, the universe has all sorts of stuff in it that we would never expect. Sure with CGI, we can 'visit' anything we can imagine.
    It's just great that there is more than that out there. Gives me hope for the future.
    • It also shows that no scientific theory can be trusted to be valid past lunch, we just never know when we'll find something new that blows the standing knowledge out of the water.

      Can it all really be random?

      • I strongly believe (pun intended) that the randomness is vital to the development and existance of life.
        Imagine if everything would be strictly ordered, what a boring place would the universe be.
        Even in society, I think that diversity is good. Different opinions make us stronger, not weaker.

        Then again, maybe I'm wrong : if you think you found something, you didn't look hard enough.


      • by ajs ( 35943 ) <> on Friday August 04, 2006 @03:40PM (#15848404) Homepage Journal
        It also shows that no scientific theory can be trusted to be valid past lunch, we just never know when we'll find something new that blows the standing knowledge out of the water.

        Hurm... well, yes and no. Theory gives us an excellent start in almost all areas, but theory is only (as a maximum) as valuable as the data on which it is based. We have very little data about the composition of our galaxy (less, even, than we do about the earth, millions of years ago), so it is not shocking that we would find major gaps in our understanding (we only just recently discovered the supermassive black hole at the center of our galaxy (and most or all others).

        Can it all really be random?

        First off, that's a non-sequitor. Second, "random" isn't the word you want there. When you are talking about large-scale processes, you can use ranomness as a tool to understand, but as we probe the nature of the universe we have consistently found that things that appear to have no order, are in fact very ordered. When you see two planetary objects orbiting one another, that's not random, it's the result of the gravitational forces exerted by those two bodies and, to increasingly lesser degrees, everything else in the universe. If it appears random, that's just becuase you had too little information about the forces involved.
      • The fact that scientific theories will change when new evidence is presented is a STRENGTH, not a weakness. It's evidence of the system WORKING. A philosophy based on empirical knowlege THRIVES on revision just as much as a philosophy based on divinely revealed knowlege resists revision. Scientists LOVE it when there is a credible challenge to existing theories, because it means there is an oppertunity to learn a lot more. This doesn't "blow what we knew out of the water." Yes, our idea of what exists in
    • Pizza Pizza (Score:2, Funny)

      by krell ( 896769 )
      No need to get all excited because Galactus phoned in to Magrathea for the two-for-one special. Different toppings on each planemo, no less.
    • The idea of planets orbiting each other doesn't seem so surprising. Even to say that the earth orbits the sun, and not vice-versa, is slightly ill-defined. The earth and sun exert equal but opposite forces on each other, so they both accelerate, but the sun is much heavier so it accelerates the earth much more. The sun's orbit of the earth is so small, it's just a wobble. But what is the precise ratio of mass where we say one body "orbits" the other?
      • It is more fair to say that the two bodies orbit their collective center of gravity.
        • And the moon orbits the earth, etc - it makes sense that a larger body orbits a smaller body, and as the difference in size approaches zero, the two bodies will orbit a virtual "center" of gravity between them (assuming their mass and density is close as well).

          With the universe being stupidly big, it's quite possible that both planets were thrown off of their orbits around larger bodies, and wandered the universe until coming into proximity with eachother getting stuck in a shared gravitational pull.
    • The idea of wandering sunless planets is old enough at least in fiction. The book "When Worlds Collide" is about a pair of rogue sunless planets which orbit each other entering the solar system and colliding with Earth. It was written in 1932. The movie [] made in 1951 is not half bad either.
    • Haldane's law:

      Not only is the universe stranger than we imagine, it's stranger than we can imagine.
  • by Lord Ender ( 156273 ) on Friday August 04, 2006 @01:29PM (#15847534) Homepage
    It's a space station!
  • Stars... (Score:5, Interesting)

    by Kaenneth ( 82978 ) on Friday August 04, 2006 @01:30PM (#15847544) Homepage Journal
    Stars can only 'ignite' when enough mass accumulates. It would make sense that often there would be chunks of smaller mass just floating around until they scoop up enough matter into their gravity well to start fusion.
    • I know almost nothing of astrophysics but that's exactly what I was thinking. We generally only aim our telescopes at stars since it helps to have a set of targets. But out there in between the bright lights I imagine there's plenty we simply don't see, either from lack of light or lack of looking. I'm probably being overly simplistic, but...
  • by russ1337 ( 938915 ) on Friday August 04, 2006 @01:32PM (#15847557)
    They go under the official name Oph 162225-240515, or Oph 1622 for short.

    I think we can just stick to "The twins"...
  • Challenging views? (Score:2, Insightful)

    by SheeEttin ( 899897 )
    I'm sorry, but what exactly does this challenge? A planet doesn't need a star to form.

    If a nebula is the right size, it may form a planet--and it doesn't care if there's any stars nearby. It is then affected by something's gravity, and goes careening off into space.

    Additionally, to make twin planets, you'd need only a nebula that's peanut-shaped, so it collapses into two bodies.
    • by Burlap ( 615181 ) on Friday August 04, 2006 @02:00PM (#15847733)
      technically they do... a planetary object by definition needs something to orbit.

      What i think you meen is that a nebula of the right size can form a stelar object that doesnt have the mass for fusion.
    • I agree. It's possible that in the vast amounts of space, variations on themes we already know to take place, occured on a larger scale.

      Everytime I hear about new scentific discovery I am reminded of Bill Engval, the comedian. He had probably the best scientific theory, that is best applied FIRST. What if it's a Dork Fish? You know just a very very warped specimen of the species and not a good representation of the whole. Yet, we base or WHOLE of knowledge off this one FREAK. Definately something to t
    • It doesn't really challenge anything meaningful, the popularized stance in the article just makes it seem that way. There's always been a simmering debate over what, exactly, a "planet" is. Other than contributing to that relatively innocuous argument over terminology, there's nothing here that was previously thought to be impossible. There's absolutely no reason a stellar object MUST form in the area of a star, nor is there any reason it can't form in the area of a star and then be ejected by some stellar
    • by kevco46 ( 607376 )
      This discovery does have some implications about how these very small objects form. The two theories are essentially (1) they form from very small clumps of dust and gas, just like our sun did but the initial clump is much smaller or (2) they started out as a larger clump, but while they are still trying to accrete much of their mass, a gravitational interaction with a larger star flings them away from the molecular cloud they were born in. Away from the main molecular cloud their is less material for them
  • by Anonymous Coward
    Other extra-solar planets were dicovered when the astronomers saw the doppler shift in their stars. These planets do not orbit stars (as far as I can tell from the article) so there's no light to see them and there isn't a star to see any "shifts". So how were these stars discovered? X-Rays? What?
    • From 9-06.html []:

      The researchers discovered the companion candidate in an optical image taken with ESO's 3.5-m New Technology Telescope at La Silla, Chile. They decided to take optical spectra and infrared images of the pair with ESO's 8.2-m Very Large Telescope to make sure that it is a true companion, instead of a foreground or background star that happens to be in the same line of sight. These follow up observations indeed confirmed that both objects are

    • While they are not sufficiently massive to spark fusion, they do, in fact radiate in the infrared range, due to gravitational contraction heating.

  • Not dark matter (Score:5, Informative)

    by Anonymous Coward on Friday August 04, 2006 @01:37PM (#15847588)
    Anticipating a possible question: no, a previously-unknown population of "planemos" can't be the dark matter astronomers are searching for. First, there were enough of them to account for the huge mass of dark matter (some 95 percent of the mass of the universe), we would have seen a lot more of them by now. "Massive compact halo objects", or basically planetoids, brown dwarfs, neutron stars, etc. have been detected (via gravitational lensing), but they are known not to comprise the majority of dark matter due to such bounds on their total mass. Furthermore, from the effects of dark matter on structure formation in the early universe, the cosmic background radiation, and other factors, it is known that "normal" matter can't account for most of the mass of dark matter, either: most of it needs to be in the form of "weakly interactive massive particles" (sort of analogous to neutrinos, except much heavier).
    • Re:Not dark matter (Score:2, Interesting)

      by jtwronski ( 465067 )
      On the somewhat off-topic of dark matter, what is the big deal with scientists searching for all this matter that we can't see? Perhaps I'm missing something really important here, but why is it so important that there might be all this matter in the universe that we can't currently detect? So what if it doesn't glow, or emit x-rays, etc. Aren't we dark matter? It stands to reason to me that the majority of mass in the universe probably isn't glowing or burning, or emitting some cosmic ray that we can d
  • Pic (Score:3, Insightful)

    by JesseL ( 107722 ) on Friday August 04, 2006 @01:38PM (#15847592) Homepage Journal
    Isn't it amazing how well the artist's impression clearly and realisticly show that the these objects are separated by "six times the distance between the Sun and Pluto"? /_41960898_planemos_203_eso.jpg []
  • by vjmurphy ( 190266 ) on Friday August 04, 2006 @01:40PM (#15847605) Homepage
    "The pair belongs to what some astronomers believe is a new class of planet-like objects floating through space; so-called planetary mass objects, or "planemos", which are not bound to stars.'"

    Once again proving that astronomers should not be naming things while drunk. Here's a handy reminder: "Remember the Planemos!"
    • Once again proving that astronomers should not be naming things while drunk. Here's a handy reminder: "Remember the Planemos!"
      The only question unanswered is: Is it pronounced "plane-mos" or "plan-e-mos"?
  • Ok so our Solar System is mostly flat. I mean, the orbits of the planets tend to follow the same orbital plane, with a notable exception of course.

    The reason the planets orbit in the same plane is the same reason rings around celestial bodies like Saturn eventually fall into a common orbital plane: gravity. As the mass collects there is something like a gyroscopic effect, causing a general influence towards the common plane.

    But.. if that's the case, why do we have a planet that doesn't follow the plane? And, also, is it slowly falling into line with the rest? (I think the answer is yes, it is, but I don't know for sure.. at least I think it should be).

    Which leads me to ask.. Was Pluto originally extra-solar? Could it have developed in this eccentric orbit if it were originally part of the solar system when it formed? Is it possible that Pluto somehow, amongst the billions of years our system has been around, floated into orbit here for good, from Out There?

    And if so, if there are enough of these free-floating masses out there, what kind of percentage of the unobservable 'dark matter' might this account for?

    Just a few of my questions,

    • by tpjunkie ( 911544 ) on Friday August 04, 2006 @02:02PM (#15847744) Journal
      pluto is thought to be a captured kuiper belt object,, meaning that some collision or gravitational interaction with a massive body brought it in towards the inner solar system, which explains its eccentric orbit which is also at a very high inclination to the plane of the ecliptic.
    • You've got questions...I've got answers

      why do we have a planet that doesn't follow the plane?

      It marches to the beat of a different drummer. Its the "alternative" planet.

      is it slowly falling into line with the rest?

      Yes, they always do.

      Was Pluto originally extra-solar?

      We were all "extra-solar" at one point or another...know what I mean.

      Could it have developed in this eccentric orbit if it were originally part of the solar system when it formed?

      If it were originally a part of the "system" then it

    • by phoenix.bam! ( 642635 ) on Friday August 04, 2006 @02:11PM (#15847802)
      You are incorrect as to why the planets are on the same elliptical plane. []
      #3 on that page is the step which explains why the solar system is on the same plane. Pluto being outside that plane is most likely it is actually a kupier belt object and was far enough out from the formation of our sun to not have fully fallen into the accretion disc.

      More information is available at [] []

      The reason your explanation doesn't work for why the planetary bodies are on the same plane is because they are all in stable orbits. To plane out into a disc they would need to still be falling towards the sun.

      Planetary rings are in the ring pattern because they follow the orbit of the object from which they were created, they are not collected and built up from smaller particles but probably the result of the destruction of a large object. []
      • Ahh hmm. It was my understanding that the accretion disk of our solar system (the planets) formed due to the combination of gravity and inertia/velocity. I.E. that's why they're all in the same orbital plane.

        The reason your explanation doesn't work for why the planetary bodies are on the same plane is because they are all in stable orbits. To plane out into a disc they would need to still be falling towards the sun.

        But aren't they getting close to the sun all the time? In effect still falling towards it
        • But aren't they getting close to the sun all the time? In effect still falling towards it? Seems like it would be perpetual motion were they not?

          They will be getting closer due to friction, however, there isn't a lot of friction on a planet moving through space.

          Also the solar wind will be providing a force to push them away - though F=ma, and F is tiny, and m is large...
        • Things moving in empty space come as close to perpetual motion as you're likely to get. However, the orbits of the planets are probably decreasing slightly over time due to the minor friction of the solar wind and mutual gravitational interactions with the other planets (especially Jupiter).

          Also, tidal distortions have an effect which slows the rotation of planets down, especially if they have a relatively big moon orbitting them, until the rotational period and the orbital period match. For example, the
  • if the 'planemos' are not part of any stellar system, how are they visible in an optical telescope? they can't generate light of their own, they can only reflect...
  • how exactly does this streach the ideas of how objects are formed in space? These "planemos" were therorized in my highschool astronomy book (and no, im not going to tell you how many years ago that was).

    To form a star: Take a whole LOT of hydrogen gas in open space... maybe add a little helium for good measure. Wait for a few million years untill the gravatational pull of the gas concentrates in in the center of the cloud. As the gas condences it gets hotter due to the collisions of the gas molicuel
  • by JamesP ( 688957 ) on Friday August 04, 2006 @01:53PM (#15847690)
    Which one is the evil twin?

    Thank you , I'll be here all evening!
  • Snakes???? (Score:5, Funny)

    by krell ( 896769 ) on Friday August 04, 2006 @02:00PM (#15847731) Journal
    Snakes, on a PLANEMO????
  • The first planemo will make a very close approach to Earth. The second will smack right into earth. But by then the spaceships we cobble together with nifty 50's retro-tech will have blasted off with the lucky few colonists to build a new civilization. Too bad with such a small gene pool they'll devolve into slack jawed mouth breathers in a few generations. Looks like the future of reality TV is assured.
  • Any Star Wars CCG fan can tell you that Kiffex [] did this long, long ago.
  • by monoqlith ( 610041 ) on Friday August 04, 2006 @02:14PM (#15847822)
    PlanemO's are actually God's cereal.
  • by plasmacutter ( 901737 ) on Friday August 04, 2006 @02:16PM (#15847835)
    so they found a binary rogue planet system... now theyre just trying to create a new jargonistic name for them so they can be in the history books.. just call a spade a spade already.. "binary rogues"... that's it..

  • If there were a ridiculous number of these 'unexpected' objects, that could explain the 'dark matter' problem, right? I mean, we can't see a bunch of rocks out in space, only stars. Perhaps there are way more rocks than burning stars.
  • I wonder what sort of light this twin object radiates that is visible through the ground telescopes.

    And, how do they know it is a twin? We can't resolve two separate points at such a distance, can't we?

  • RTFA? (Score:3, Informative)

    by Dieppe ( 668614 ) on Friday August 04, 2006 @02:28PM (#15847938) Homepage
    For people who didn't RTFA, the two planets are about 6x the distance from the Sun to Pluto. The image in the article shows two large happy planets practically next to each other.

    Six times the distance from the Sun to Pluto. If you're on one planet you might be lucky to see the tiny dot of the other planet in the night's sky... I don't recall if it said they were orbiting a star (for light) or not. So even the picture is misleading.

    • As I recall, you need a pretty good telescope to see Pluto when you know where it is. 6x as far means it'll be 200 times dimmer (roughly?) *and* you don't have a nice convenient nearby source of light to illuminate it since they're both swinging around out on their own. I think you'd have to be lucky indeed.
  • While it appears they believe these two planet-like objects formed together outside of a proper solar system, stray planets floating through space along are probably not all that rare, particularly smaller single ones. The current thinking in solar system development is that Jupiter+ sized planets sometimes move inward towards their host star as the planets develop. When they do this, planets whose orbits they come near will generally either get flung into the host star or outside of the system completely f
  • by Joebert ( 946227 ) on Friday August 04, 2006 @03:50PM (#15848476) Homepage
    Smell that ?
    It's the smell of rendering farms heating up at Pixar.
  • Not so strange (Score:3, Interesting)

    by FridayBob ( 619244 ) on Friday August 04, 2006 @04:59PM (#15848888) Homepage
    Although it's interesting that we've now been able to observe such a pair of dim objects in this configuration, I see nothing strange about its existence. Astronomers have known about binary (and trinary) star systems for ages, but those were always easy to spot because they're so luminous. Brown dwarfs, on the other hand, are much harder to find, but thanks to modern technology we've found quite a few and astronomers now believe that they are in general quite numerous. So, what's so strange about two brown dwarfs orbiting one another? Nothing, really. It may be the first time we've found a binary system like this, sure -- great! -- but it's not strange at all; that's just an adjective thrown in by the media to spice the story.

Today is a good day for information-gathering. Read someone else's mail file.