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Planets Without Stars or Mini-Solar Systems? 149

Posted by timothy from the ronin-played-by-planet-di-niro dept.
iamlucky13 writes "An article today on space.com discusses the discovery of 6 objects by the European Southern Observatory in Chile that are smaller than typical brown dwarfs, larger than Jupiter, and not orbiting any stars. The objects are surrounded by disks of gas and dust possibly similar to the early solar system. In addition to presenting astronomers with a new group of objects to study, the finding also deepens the debate over what makes a planet. The scientists responsible for the discovery sidestep the question by calling them 'Planetary Mass Objects,' or planemos."
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Planets Without Stars or Mini-Solar Systems? More

Planets Without Stars or Mini-Solar Systems?

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  • Planimals? Planetimals? (Score:3, Funny)

    by xski ( 113281 ) on Monday June 05, 2006 @08:23PM (#15476704)

    Ok, it doesn't really mesh with the whole 'Mass Object' extension but I'm fairly certain the general public could deal with it much better this way. Besides, if you throw something like 'planemos' out to Jack & Jenny Sixpack, Planimals is the innevitable result.

    -xski

  • True 'planets' then (Score:5, Interesting)

    by Anonymous Coward on Monday June 05, 2006 @08:28PM (#15476723)
    As the word planet actually means "wanderer".

    • Comment removed (Score:5, Interesting)

      by account_deleted ( 4530225 ) on Monday June 05, 2006 @08:30PM (#15476738)
      Comment removed based on user account deletion

      • Re:True 'planets' then (Score:4, Interesting)

        by fossa ( 212602 ) <pat7.gmx@net> on Monday June 05, 2006 @09:06PM (#15476894) Journal

        Not knowing the time scales involved, I'm just going to throw this out as a possibility: if the orbital period of these odd planets around the galaxy is large enough, then the gravitational landscape on each revolution will be so different that the odd planet will hardly have a regular orbit. Alternatively, could it not eventually be trapped by a star? If so, one could hardly call its journey from wherever it started to the capturing star an orderly orbit.

        • Alternatively, could it not eventually be trapped by a star? If so, one could hardly call its journey from wherever it started to the capturing star an orderly orbit.

          There is a theory that this is what happened to Pluto [wikipedia.org]. Recall that Pluto has a completely different composition to any other planet in our solar system and many argue it to be a comet or other such body. It's orbit is inclined to the plane upon which the rest of the solar system is found, and during a short period of it's orbit it is closer

          • There aren't any serious suggestions, at least in modern times, that Pluto came from outside the solar system. There are many more objects like Pluto in the Kuiper Belt and beyond, in the "scattered disk", and perhaps even in the Oort cloud. But all of this is still part of our solar system. Pluto falls within the Kuiper Belt and is classified as a Kuiper Belt Object. Its orbit might have changed since the solar system was formed, perhaps as a result of gravitational interaction with Neptune, but that's
      • These planets wouldn't be in the formation of a Kemplerer Rosette?

        To any Pierson's Puppeteer: I'm over here! (though, I do not know how much pure luck was involved in my birth...)

        (for those, who still don't get it:

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

        )
    • For the ancient Greeks a planet was any object that appeared to wander against the field of fixed stars that made up the night sky (asteres planetai "wandering stars") (cf http://en.wikipedia.org/wiki/Definition_of_planet [wikipedia.org] )

      The problem with that definition is that the sun was initially included as a planet because it looked like moving around the stars.

      So when the initial definition of a word is based on false assumptions, it is probably hard to save the ass of that word with further discoveries 3000 y

    • Yeah, but planet + emo == planemo :]

      So they're angsty "teenage" planets wandering through dark places for no particular reason...
    • Am I the only one thinking this is a Death Star? While we're all debating orbital trajectory and definition, Alderaan is being mercilessly pummeled. Sad, just sad.

    • actually? (Score:1, Informative)

      by Anonymous Coward
      Uh... The word planet actually means:
      1. A nonluminous celestial body larger than an asteroid or comet, illuminated by light from a star, such as the sun, around which it revolves. In the solar system there are nine known planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto.
      2. One of the seven celestial bodies, Mercury, Venus, the moon, the sun, Mars, Jupiter, and Saturn, visible to the naked eye and thought by ancient astronomers to revolve in the heavens about a fixed Earth and a

  • Dark Matter (Score:5, Interesting)

    by SB5 ( 165464 ) <freebirdpat@hotm[ ].com ['ail' in gap]> on Monday June 05, 2006 @08:30PM (#15476741)
    Could these make up the hypothesized "Dark Matter"? Not these 6 objects specifically but objects like them.

    I guess the question is how many of these would it take fill up the "dark matter" quotient we think exists.

    • Re:Dark Matter (Score:5, Informative)

      by Anonymous Coward on Monday June 05, 2006 @08:57PM (#15476861)
      This is an excellent question. The idea of objects like these comprising dark matter has been tested with the MACHO project ( http://wwwmacho.mcmaster.ca/ [mcmaster.ca] ) which attempts to detect objects like this through gravitational lensing events. Unfortunately, the data from this experiment seem to suggest that they don't comprise enough mass to explain Milky Way observations.

      • Re:Dark Matter (Score:5, Informative)

        by hogghogg ( 791053 ) on Monday June 05, 2006 @10:19PM (#15477198) Homepage Journal
        That's correct, though the MACHO experiment places its best limits on much more massive objects than Jupiters; for now it is conceivable that such objects could be a significant part of the dark matter. OTOH, there is no way (without huge modifications to what we know about the early universe) to make the majority of the dark matter anything (dust, rocks, planetesimals, planets, brown dwarfs, white dwarfs, neutron stars) that are made from atoms; we now know that the atomic component of the Universe must be only a few percent of the total. So though these could be part of the dark matter, they can't be all of it.
      • I like my personal theory on Dark Matter.

        It's all Dyson Spheres [wikipedia.org]
    • It doesn't look like it--they would have to occur in vast quantities within galaxies and they just don't seem to.

      If they did, it would be great, because it would mean that would be lots of planets between here and nearby stars. That would make interstellar travel considerably easier because humanity could move outwards very gradually.
    • No, the question is:

      Is the dark matter quotient half full or half empty?

    • Re:Dark Matter (Score:4, Informative)

      by hogghogg ( 791053 ) on Monday June 05, 2006 @10:23PM (#15477209) Homepage Journal
      If these things made up the "dark matter" then it wouldn't be dark -- these objects (it might not be clear from the article) were found because they emit strongly in the infrared. In short, they can't make up the majority of the dark matter, either observationally or theoretically. Good idea, though.
      • I thought that dark matter was originally called such simply because we couldn't see it? If that is the case, then surely anything we haven't yet observed could qualify?
      • the dark matter

        One of my minor crusades on /. is to encourage people--especially astonomers--to stop talking about "the" dark matter. There are several different dark matter problems, and they may well have quite different solutions, some of them a lot more exotic than others. Galactic dark matter is (at least potentially) baryonic. Dark matter on larger scales is almost certainly not baryonic unless we've really goofed on the whole primordial nucleosynthesis thing.

        The discovery of these small objects s
    • They absolutely do. "Dark Matter" isn't anything fancy... It just means "matter in space that doesn't glow". That's bound to include space dust, brown dwarfs, cold gasses, and planets (orbiting stars or otherwise). The question about dark matter is really about how there can be so much of it-- the mystery being that the things I listed aren't usually taken to account for enough mass.

  • Why haven't I heard about this before? (Score:3, Funny)

    by Flimzy ( 657419 ) on Monday June 05, 2006 @08:30PM (#15476743)
    I've watched every episode of Star Trek, and don't remember these planemos ever being mentioned!

  • in Chile? (Score:2, Funny)

    by Russ Nelson ( 33911 )
    If the Observatory discovered them in Chile, then they are *definitely* orbiting the Sun. Or maybe there's a problem with his sentence structure?

  • Why is this not the norm? (Score:3, Interesting)

    by Anonymous Coward on Monday June 05, 2006 @08:45PM (#15476800)
    Actually I find it more interesting this isn't more common (or is it? dun dun daan), because it really doesnt take much to escape the gravity of many stars. Planetary formation aside, given that stars whiz by each other they should be slingshotting crap away from each other.

    For example, really how large a whack from a body with the right vectors is needed to send pluto escaping off in some mad direction? Anyone care to calculate how much force is needed to do it?

    • Anyone care to calculate how much force is needed to do it?

      A whole bunch. In round figures.
    • For example, really how large a whack from a body with the right vectors is needed to send pluto escaping off in some mad direction?

      Since you stipulated that the body would have the right vectors (relative speed and direction) the whack need only be calculated in terms of mass. According to my careful and precise calculations it would take a whack with the mass of exactly 733433 Volkswagens per Pluto. This is to send Pluto escaping off in some direction. Further calculation is needed to determine if said
    • It is, in theory, possible that this has already happened to some other object in our solar system long ago. However, the problem of exponentially sensitive initial conditions means we can never actually know.
    • If I understand the article, it sounds like the presence of a dust disk suggests that these bodies formed on their own. The dust is similar to the accretion disk observed around young stars that fuels their growth and possibly the formation of orbiting planets. In theory, if a local knot of gas and dust was too small to form even a brown drawf, you get these planemos. A very small jump of reason suggests there may even by binary planemos or planemos with "moons."

  • Planet or moon? (Score:4, Funny)

    by Anonymous Coward on Monday June 05, 2006 @08:48PM (#15476815)
    That's no moon....
  • Wouldn't the correct term be "star system" or "stellar system" [wikipedia.org]?

    Solar system [wikipedia.org] refers to the Sun and its planets.
  • Are we certain its a planet, what if its a alien spaceship?, it says
    " The objects are surrounded by disks of gas and dust"

  • the finding also deepens the debate over what make (Score:5, Insightful)

    by exp(pi*sqrt(163)) ( 613870 ) on Monday June 05, 2006 @09:07PM (#15476898) Journal
    the finding also deepens the debate over what makes a planet
    That must be 'deepens' as in the question of how many angels you can fit on a pinhead is deepened by the suggestion that maybe some angels are overweight.

    There is nothing deep about what to call by the name 'planet'. Once there was a clear delineation between planets and non-planets. Now there isn't because we've seen objects that straddle the divide set by the old definition. Just define some new words. If astronomers can solve the solar neutrino problem then surely they can solve the 'define planet' problem. Reminds me of Wadler's Law [blogspot.com].

    • Re:the finding also deepens the debate over what m (Score:1, Insightful)

      by Anonymous Coward
      "If astronomers can solve the solar neutrino problem then surely they can solve the 'define planet' problem."

      Well, we could announce some proclamation from the balcony of the IAU's [iau.org] Mobile Oppression Palace, but since it's such a complete astronomical non-issue (what something's called makes no difference to how you study it) don't you think it's nice to let the people who care enough to debate it decide?

      So, over to you!

    • No need. (Score:5, Interesting)

      by jd ( 1658 ) <imipak@ y a hoo.com> on Monday June 05, 2006 @11:16PM (#15477403) Homepage Journal
      I don't see what the fuss is about, when it comes to planets, planetoids, etc. The problem is that astronomers have been using extremely an trivial value (diameter) to determine what to call non-stars, and use an equally trivial pair of values (spectral type and class) to determine star types. This seems to me to violate one of the core principles behind naming schemes (grouping in order to simplify understanding) and one of the fundamental tenants of science (keep things as simple as possible, but no simpler).

      The Periodic Table of the Elements makes a lot of sense, because you can make a lot of predictions about the properties of an element based on where it is in the table. There are some oddities, sure, but by and large it is an extremely intuitive system. By comparison, knowing that a star is K or G tells you very little. You can make some inferences, by factoring in the abundances of the elements, the diameter of the star, the overall distribution of the electromagnetic radiation, etc, but if you're going to have to add in vast amounts of additional information to get anywhere, you might as well use that information in the name and have done with it.

      For planets, asteroids, etc, it's much the same thing. By using too little information to determine the classification, you end up having to add vast amounts more information later on to produce subcategories, exceptions or new names entirely. That makes no sense to me whatsoever. Even a good naming system will need additions made to it, but it should be consistant with what is already there, and it should be easy to understand the relationships.

      Since this is about planets, I'll use those as an illustration. Planets form around stars from the debris in the accretion disk, plus captured material from the stellar nursery in which the star formed, minus material "evaporated" from the system by the solar winds accelerating it, and minus material captured by other stars or gravitational sources. The process of condensing planets is slow, though apparently not as slow as once thought, which means that the material in the accretion disk will be sorted. In our own solar system, it seems to be that heavier elements are more common close to the sun and lighter ones are more common further away. (Mercury is unbelievably dense, for example, whereas Pluto seems to be little more than an iceball.)

      However, because you need less energy to accelerate a lower mass, and because elemental hydrogen only forms a solid under extreme pressures, these will ALL have abundances of elements that are skewed (possibly by a lot, for inner planets, as the solar winds are much stronger) from the ratios observed on much larger scales (say, in the galaxy or the observable universe). Stars, on the other hand, are mostly composed of the extremely light elements and fit the expected abundances very nicely. As the gravitational field is reduced, the skew should increase, as it would require that much less energy for something to be ripped away, if it's free. (Obviously, hydrogen that has reacted with oxygen to form water is going to require much more energy than elemental hydrogen alone.) So, the composition tells us a lot about where something forms, how quickly it accumulated mass and how long it took. It would seem obvious, then, that composition should bear a major role in deciding what to call something.

      The other "obvious" one would be structure. The "asteroid" recently observed to be 45% empty space (sand is 25%) would probably merit a new classification. Most asteroids probably have multiple "centers" around which they have congealed/collided. Certainly, the two comets that have broken up have had multiple centers, not a single rocky core. By comparison, the gas giants have a single center (duh!), as does the Earth and Venus, probably Mars as well, not sure if there's enough data on the others. But even with that, we can clearly see a logical distinction (as opposed to an arbitrary one) that can clearly distinguish between two very

    • The problem here is that people want to put everything into neat little boxes where all the objects are alike and they are all different from objects in other boxes. This discrete nature of thinking is the root problem, and some people spend way too much time trying to figure out which box to put it in instead of trying to understanding the object.

      This applies to every endeavor of human thought, not just science.

  • This new slashdot.org template sucks!!!!!! (Score:1)

    by Anonymous Coward
    The old one was warm, and familiar. This one, feels cold.. I dunno, I wont be back as often..

  • Star systems without a star (Score:3, Interesting)

    by RKenshin1 ( 899412 ) on Monday June 05, 2006 @09:40PM (#15477023)
    I suppose it makes sense that a planetary system could form in the same manner as ours,
    but lack the mass to ignite a sustained fusion reaction in the core of the system.

    How many others could be out there that we can't see?

  • Hmmm... (Score:3, Insightful)

    by Liam Slider ( 908600 ) on Monday June 05, 2006 @09:54PM (#15477096)
    Maybe the scientists should simply call them what they're already called....rogue planets.
    • But they're not single planets, but in fact an entire star system sans the star. To me a rogue planet doesn't suggest a cohesive system, but in fact a single planet (with or without moons) that have no other body related to it.
    • So they are rogue planets and they don't have nuclear capabilities. Hope they don't have oil as well, or they're in for a world of hurt.
    • Like Mars. Oh, wait, that's a rouge planet...
  • ... to the question of what's a "planet" is the suggestion that we define it as one of the 9 objects that orbit our sun and are listed in American grade-school science texts.

    This would settle the question forever, since it would immediately follow from the definition that there can't be any more planets anywhere in the universe.

    Those troube-making astronomers would just have to invent a new term for similar objects elsewhere in the universe. Or in our solar system, for that matter. It's about time they di
    • From my very biased point of view, I really don't give a damn if it's called a brown dwarf or a planet.

      The taxonomy of celestrial objects are not exactly scientifically done in astronomy,IMHO. But the bottom line? The key parameters for these objects are: mass, density and temperature. These three parameters would *fairly uniquely* identify the object (and more descriptive), no matter what scientific language you speak of.

      Sometimes I just hope that astronomers just quit being catalogue makers and act more
  • In other news, Dr. Sven Bronson announced that two [wikipedia.org] of the newly-discovered Planemos may be headed in our general direction. "Mankind may be facing its greatest danger yet," the renowned astronomer said. However, world governments have so far received his predictions with skepticism [imdb.com].

  • In Related News . . . (Score:4, Funny)

    by Dausha ( 546002 ) on Monday June 05, 2006 @10:01PM (#15477135) Homepage
    In related news, Chilean astronomers have realized that their cleaning crew has not been cleaning the telescope.
  • ...of Deep Space 9... "A Rogue Planet." Lookout! I think its the homeworld of the Founders. You red-shirts better get the hell out of there...

  • Fun for the kids~! (Score:2, Interesting)

    by Zaphod2016 ( 971897 )

    At the risk of being modded OT, this article reminded me of an awesome little trick an old physics teacher did to help us visualize how we got from the big bang to planet earth.

    Take a small bowl, fill it with water. Then, add a handfull of dark sand. Let the sand sort of float in "space" for a bit, moving the water enough to keep everything floating.

    Now, to "play God", simply twirl the water counter-clockwise (or vice versa if you live under the equator) and remove your hand. Behold: your universe of sa

  • It would be funny if they were just using a lower power eyepeice on their telescope and they were just like "hey man... that solar system looks really small... hahaha... silly astronomers, always mixing up their optics.

  • The Planemo Effect (Score:2, Informative)

    by Nerd_52637 ( 938469 )
    A planemo, short for Planetary Mass Object, is a celestial object which is solitary and orbited by matter as if it were a star, but is actually a planet. Studies have shown that humans cannot differentiate between real active stars and these inert planets, wishing on both equally. Researchers call this the "Planemo Effect"
  • It doesn't really matter. These objects, while interesting, and theoretically may have some useful information to discover, are going to reflect the same end result. They are what they are: objects in space. Debating the name or generalization we place these objects won't make a difference.
    Or maybe I'm just a jerk today.

  • Planemos? (Score:2, Funny)

    by WgT2 ( 591074 )

    Must not have been any Spaniards at that observatory... at least none with any clout.

    Unless there are and they're planning [wordreference.com] to name it something else later.

  • do these planemos as they call it, run linux? now for my sig. www.mymegastores.com -- go there if you really want to move out of your parents basement
    • On a more serious note, Who is to say that there isnt an opposite to the structure of solar systems, where there are sun like objects orbiting either nothing (like a binary star) or a single planet ....
      try two at my sig... www.mymegastores.com -- your solution for getting out of your parent's basement

  • duh (Score:2)

    by luna69 ( 529007 ) *
    Makes sense to me.

    Stuff coalesces. Some is dense, some is not. that which is suficiently dense makes stellar systems. That which is mot does not. Pretty simple, I think.

    (IAAA - 'I am an astronomer')
  • the finding also deepens the debate over what makes a planet

    Hmm, and I was wondering if the finding should start debate on what makes a star or stellar object, silly me
  • An article today on space.com discusses the discovery of 6 objects [CC] by the European Southern Observatory [CC] in Chile that are smaller than typical brown dwarfs, larger than Jupiter, and not orbiting any stars. ...
    In addition to presenting astronomers with a new group of objects to study, the finding also deepens the debate over what makes a planet.

    "You humans, when're you gonna learn that size doesn't matter? Just 'cause something's important doesn't mean it's not very, very small."
  • "Planet" comes from the greek word "planitis" which means "adrift in a space". The word "plane" also comes from that root. So the term "planet" is correct for these celestial bodies that do not orbit a star.
  • I propose we call it the "Pupeteer Fleet Worlds" and be done with it.
  • They're missing some vital informtion from their observations........what's the damned weather like?

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