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Earth Science

Analysis Suggests Solar System Contains Massive Trans-Neptunian Objects 170

BarbaraHudson writes NBC News reports that at least two planets larger than Earth likely lurk far beyond Pluto, just waiting to be discovered, a new analysis of the orbits of "extreme trans-Neptunian objects" (ETNOs) suggests. The potential undiscovered worlds would be more massive than Earth and would lie about 200 AU or more from the sun — so far away that they'd be very difficult, if not impossible, to spot with current instruments. "The exact number is uncertain, given that the data that we have is limited, but our calculations suggest that there are at least two planets, and probably more, within the confines of our solar system," lead author Carlos de la Fuente Marcos, of the Complutense University of Madrid, said. (Here's the longer version at Space.com.)
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Analysis Suggests Solar System Contains Massive Trans-Neptunian Objects

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  • Riiiiight. (Score:2, Informative)

    Our ability to discern planetary positions has largely been based on our understanding of orbital dynamics and looking for protuberances in the motions of known, directly observed objects that were naked eye observable. This technique has been used since the 16th century and led to discoveries of all Planets, Planetoids, various Asteroids, Comets, and Plutoids ever since without the need of direct imaging; just some very cool math...
    • by Anonymous Coward on Saturday January 17, 2015 @04:05PM (#48840359)

      are your protuberances a little bit perturbed?

      • Seeing these protuberances on slashdot perturbs me a little. But I would be seriously perturbed to see protuberances of astronomical size.

    • Yep, but the most recent line of thought has been that all the previously suspicious things about known outer solar system orbits have already been explained away. At least some serious upper bounds have been put on the masses of the potential objects (and lower bounds on their distances). Whether this work on TNOs will withstand close scrutiny is the question to ask.
    • by Anonymous Coward

      Protuberances? That would mean much like Uranus, they are prolapsed.

    • Most new discoveries are still done through imaging rather than maths. It's fairly automated these days though.
    • Yep, 400 years the math has been right... and we only discovered Neptune 169 years ago. Pluto varies between 29 AU and 49 AU from Sol, depending on where it is in it's 248 year elliptical orbit. These hypothetical planets are at least 200 AU from the Sol and have very slow and large orbits taking between 1800 and 12000 years to complete.

      Our math has worked well for 400 years... but how will it hold up in 400K years?

    • Re:Riiiiight. (Score:5, Interesting)

      by Solandri ( 704621 ) on Saturday January 17, 2015 @06:25PM (#48841077)

      This technique has been used since the 16th century and led to discoveries of all Planets, Planetoids, various Asteroids, Comets, and Plutoids ever since without the need of direct imaging; just some very cool math...

      I don't think orbital dynamics has ever been used to discover an asteroid or comet or trans-Neptunian object. Certainly it's used to confirm their orbits (I've done that myself, freezing my ass off overnight taking a glass photographic plate, then measuring how much a small dot moved night to night). But asteroids have too little mass to to appreciably change the orbits of the larger planets. Ceres (along with a lot of other asteroids in the asteroid belt) in particular was discovered by blind luck by people searching almost at random for another planet between Mars and Jupiter. So to for that matter was Pluto - people were chasing what turned out to be an error in Neptune's calculated mass [wikipedia.org], and Pluto just happened to be near the spot that error predicted at the time they were looking.

      Comets are discovered by (obsessed) people scanning the sky every night for a fuzzy dot that shouldn't be there. It's actually the same process as for asteroids (except now you have a computer do the observation instead of freezing your ass off like I did), and if the orbital calculations say it's a highly elliptical orbit instead of circular, you have a comet. The gas jets from vaporizing material as they approach the sun (which gives them their "tail) are pointed in random directions, and perturbs their orbit enough to make precise orbital calculations useless. Only general calculations like Halley's Comet returning every 86 years work.

      Orbital calculations work well for (A) objects which are relatively close together since gravity decreases as the inverse square of distance, and (B) have relatively short orbital periods since this means they move faster and thus generate a larger measurable motion against the background stars. Neither of these hold true for trans-Neptunan objects.

      If you subscribe to the theory that the solar system started out as a cloud of matter, and a slightly larger lump somewhere happened to coalesce into the sun by gravity, then it makes sense that the further you go out, the more material there is simply because of geometry. The volume of space (restricted to near the plane of the solar system) goes up as the square of the distance from the sun. While the length of the orbit only goes up proportional to the radius. So there must be more stuff in the outer solar system than in the inner. It's just spread out more.

      • by rtb61 ( 674572 )

        You left out solar wind https://en.wikipedia.org/wiki/... [wikipedia.org] which from the moment of stellar ignition creates a wave which concentrates the dust cloud promoting coalescence into gravitational masses and those masses create turbulence within that dust cloud promoting the formation of comets. So the inner model is planets cores have formed prior to stellar ignition and upon ignition those cores get their final coat. Planets that do not fit that model are shaped by catastrophic impact of one form or another, a

      • Try the discovery of Pluto, which was predicted from orbital irregularities of Neptune, which as also predicted because of orbital irregularities of Uranus.
      • Thanks for taking the time to post this. I'm glad your post was modded up. I have a casual, uneducated interest in things in space, and snippets like this are interesting to me. (unlike a lot of /. posts, I'm not being sarcastic)
      • by Pulzar ( 81031 )

        Comets are discovered by (obsessed) people scanning the sky every night for a fuzzy dot that shouldn't be there.

        I'm completely ignorant on this topic.. but that sounds like something that computers should be able to do easily, no?

      • Doesn't the tail of a comet always point directly away from the sun?

    • ...and for all the GN's out there, a protuberance is a special case of a perturbation.

  • Yuggoth (Score:1, Troll)

    by chill ( 34294 )

    Beware! This heralds the return of the Great Old Ones! (Just in time for the U.S. 2016 election season it seems.)

    Keep an eye out for Mi-Go.

  • by Anonymous Coward

    Seriously though, if such a planet did exist and the had an orbit that brought it near our planet once every so many thousnads of years, what effect would it have as it passed near us? Look at the effect the moon has on our planet and think about something larger than Earth passing by.

    • by Urkki ( 668283 ) on Saturday January 17, 2015 @03:32PM (#48840183)

      I think Jupiter makes sure any highly elliptical orbit coming near Jupiter's orbit would not last too many orbits before having it's orbit radically changed, like happens with comets sooner or later if they survive long enough otherwise.

    • by Teun ( 17872 )
      If such existed it would have passed us before and left obvious traces.
      • The obvious traces are everywhere, we just choose to ignore them and think they were man-made.

        • by JWSmythe ( 446288 ) <jwsmythe AT jwsmythe DOT com> on Saturday January 17, 2015 @08:22PM (#48841853) Homepage Journal

          Everywhere is relative. There are an estimated 5 trillion habitable planets in the known universe. We've mostly explored one. On our closest neighbors, we've done roughly the equivalent of checking your back yard and saying "There are no whales". Well, unless you happen to have whales in your yard, then we'll say "... no elephants". :)

          If there is/was life on other planets, it is very likely not to be in our solar system. Even if there was an species that achieved space travel, and spent millions of years settling on millions of planets, it's *still* not very likely they'd be found on one in our solar system.

          Even if we found one, would we know what we're looking at? Since rock seems to be pretty abundant in the tiny speck of space that we've explored, a sand and rock covered hull of a spacecraft would be reasonable. That would help protect from micro-meteors and other hazards. If one crashed on a neighboring planet even 10,000 years ago, would just look like rock. Heck, if one crashed on Earth, it would still look like a rock.

          Is this space craft remains, or a natural formation? [tripadvisor.com]

          No, I don't believe it's a crashed spaceship. It's just a rock. But since we don't exactly do thorough core samples on every large rock on the planet (and under the surface), we wouldn't know if it was.

          • This looks like a photo of the rough pass of a CNC milling operation that has gone through a very bad resizing routine, probably nearest-neighbor interpolation.

          • by plopez ( 54068 ) on Saturday January 17, 2015 @11:05PM (#48842511) Journal

            "We've mostly explored one"

            Not even close to 'mostly'. The land areas often have areas very little understood, we can't find a crashed airliner in the ocean, we know very little of the crust though some discoveries of extremophiles underground hint at some weird biology and chemistry, and can't even get sol microbes into the lab without killling them. Before we try to understand other planets it might be a good idea to understand Earth first.

            • We've explored more of this rock than any other. That's the "mostly".

              Finding the lost airliner isn't a matter of lack of exploration. That is, we can't recheck an entire ocean in a short period to see if the airliner is there now. I believe that part of the ocean was already mapped, so it has already been "explored".

              Your airplane argument would be like saying you haven't explored your back yard, if someone tossed a beer can over the fence yesterday, and you didn't know about it.

              BTW, I tossed a beer ca

      • by dbreeze ( 228599 )

        Like the records of some ancient civilizations maybe....?

  • by HangingChad ( 677530 ) on Saturday January 17, 2015 @03:16PM (#48840067) Homepage

    I think Pluto got robbed.

    • It has not cleared it's orbit of debris and Eris is in the same boat yet LARGER than Pluto.... how is Pluto a planet then?

      • Re: (Score:2, Funny)

        by Anonymous Coward

        Pluto has tenure.

      • by jc42 ( 318812 )

        It has not cleared it's orbit of debris and Eris is in the same boat yet LARGER than Pluto.... how is Pluto a planet then?

        Neither has Earth; there's a rather large, bright rock visible in our sky about half the time. ;-)

        Seriously, though, it's probably just a matter of time before a rock bigger than Earth is discovered out in the Kuiper belt and/or the Oort Cloud, and chances are pretty slim that its orbit will be "cleared" of rubble. This will either put an end to the current (somewhat bogus) definition of "planet", or it will cause the debate over what's a planet and what's not to bumble on indefinitely.

        The most likely

        • The most likely result will be that astronomers will eventually reject the term "planet" entirely. Sorta like how, a few centuries back, they rejected the older term "astrology", due to all its baggage and mis-use by pseudo-scientists and charlatans.

          You realize that you are implying that the astronomers who voted in the current astronomical definition of planet are all either psuedo-scientists or charlatans?

          That raises some very serious thought-provoking questions. IMHO, using only common sense and no optical assistance mechanisms, it looks to me like they are probably pseudo-scientists, and not charlatans.

          • by jc42 ( 318812 )

            The most likely result will be that astronomers will eventually reject the term "planet" entirely. Sorta like how, a few centuries back, they rejected the older term "astrology", due to all its baggage and mis-use by pseudo-scientists and charlatans.

            You realize that you are implying that the astronomers who voted in the current astronomical definition of planet are all either psuedo-scientists or charlatans?

            That raises some very serious thought-provoking questions. IMHO, using only common sense and no optical assistance mechanisms, it looks to me like they are probably pseudo-scientists, and not charlatans.

            Well, they apparently spent some time in meetings of an international organization discussing the definition of "planet", when they could have been doing actual scientific work. ;-)

            Of course, sometimes terminology is important scientifically, and it's worthwhile spending time to get it right. But they were mocked by other actual astronomers pointing out that any term that includes both Mercury and Jupiter but not some objects with intermediate properties must be an absolutely worthless term for any scie

    • I wonder what they're going to call these new objects, because they'll probably find a reason not to call them planets just like they did for Pluto.

      They're too big to be dwarf planets... Maybe elf planets?

      • Troll planets would be nice.
        • by jd2112 ( 1535857 )

          Troll planets would be nice.

          No thanks, we have enough lurking on the Internet. We don't need whole planets of them.

          • by DeBaas ( 470886 )

            Indeed if Elon Musk connects a planet full of them to our internet, we're really fscked .....

        • "Troll planets would be nice."

          And because of the latency, the inhabitants would be enable to form coherent ripostes to our posts.

      • by 7bit ( 1031746 ) on Saturday January 17, 2015 @04:23PM (#48840449)

        I wonder what they're going to call these new objects, because they'll probably find a reason not to call them planets just like they did for Pluto.

        They're too big to be dwarf planets... Maybe elf planets?

        Perhaps KP's, Kuiper Planets. Which could start a whole new Planetary naming system based on regional distance from a star instead of what we have now. Everything round + blah between the Star and it's local Kuiper Belt type region would be either an Inner Planet or Solar Planet, everything otherwise fitting that definition but within the Kuiper Belt would be a Kuiper Planet and anything further than that would be an Oort Planet.

        That might even allow Pluto to be reclassified as a planet again, either a Solar Planet or Kuiper Planet. I really think this system, plus other basic details like roundness etc, could be a more useful system. It would also allow a way to keep the number of planets more manageable since we could mostly focus on the Inner/Solar Planet count for general public use without the number of them being too high to manage.

        New Planet types based on Region/Distance from star:

        Inner Planet or Solar Planet
        Kuiper Planet
        Oort Planet

        btw: I made a post as anon under the same parent post before this, then thought I should log in and elaborate. The previous post was:

        " They'll probably be called KP's. Kuiper Planets."

        • That seems like a really good idea, sorry I have no mode points to promote.

        • Perhaps KP's, Kuiper Planets. Which could start a whole new Planetary naming system based on regional distance from a star instead of what we have now. Everything round + blah between the Star and it's local Kuiper Belt type region would be either an Inner Planet or Solar Planet, everything otherwise fitting that definition but within the Kuiper Belt would be a Kuiper Planet and anything further than that would be an Oort Planet.

          That might even allow Pluto to be reclassified as a planet again, either a Solar Planet or Kuiper Planet. I really think this system, plus other basic details like roundness etc, could be a more useful system. It would also allow a way to keep the number of planets more manageable since we could mostly focus on the Inner/Solar Planet count for general public use without the number of them being too high to manage.

          New Planet types based on Region/Distance from star:

          Inner Planet or Solar Planet
          Kuiper Planet
          Oort Planet

          btw: I made a post as anon under the same parent post before this, then thought I should log in and elaborate. The previous post was:

          " They'll probably be called KP's. Kuiper Planets."

          It could be simplified even further yet while still retaining the benefit of greater number manageability for the public, which seems to be a concern for those making the definitions, while also giving actual useful information about the planet in its Type name.

          Define a Planetary Region around a star, that would apply to all stars (actual distance per star could vary depending on Factors), in which Planetary objects would be called "Inner Planets" and one more region beyond it in distance where such same ty

          • by darkain ( 749283 )

            This is starting to sound a lot like Sailor Moon with the Inner vs Outer Senshi.

          • The alchemists did something like this, on the road to the periodic table of the elements. So it could definitely be a useful way to develop telescopic science.

            In a few decades we could then make a distinction between astronomers who accept a rationally based taxonomy of orbital objects, and "alastronomers" whose thought processes are mired in the old school searches for definitions that make distinctions between Pluto, Ceres, etc and Mercury, Mars, etc. Not to mention the hair-splitting the alastronomers

            • Not to mention the hair-splitting the alastronomers use to keep from admitting that the Earth and Moon are a binary planet such that the orbit of either one around Sol has a strong sinusoidal component.

              I thought the distinction was that the center of the Earth and Moon's mass was still within the physical circumstance of the planet. While binary planets have that center of mass somewhere between the planet's. That doesn't seem like splitting hairs to me. That seems to be a pretty clear distinction.

        • by Tablizer ( 95088 )

          Mort calling Oort. Mort calling Oort. Manu Manu!

        • There is a general dispute in taxonomy between "lumpers" and splitters" - people who say "this, this and this share these characteristics, and so I lump them together in one taxon" versus those who say "this, this and this differ in these characteristics, and so I split them into these taxa".

          You're evidently a splitter. No disrespect about that - it's a defensible position (see above). But being a lumper is also a defensible position (see above).

          The important things that you need for designing a taxonomy

      • They will be known as "midget planets", I would think.

        Except for the ones that are larger than Earth. Those will be taxonomy busters.

    • by dissy ( 172727 )

      Until you can name all hundred thousand of the "planets" in our solar system, we won't be using your definition of planet.

      Why do you insist 3rd graders should be able to recite all hundred thousand planets from memory yet refuse to do so yourself even with the Internet as your reference?

  • Planets? (Score:4, Insightful)

    by Sperbels ( 1008585 ) on Saturday January 17, 2015 @03:19PM (#48840095)
    At that range, you have to wonder enough time has elapsed since the formation of the solar system for them to have "cleared the neighborhood" around their orbits.
    • Plenty if you assume the orbital period to be around 5,000 years (see e.g. 2012_VP113 [wikipedia.org])
      • This is actually a valid question for the transneptunian space. I vaguely recall that between the times and spaces involved, the transneptunian space may not have "aged" to the same extent that the inner parts of the Solar System have. There simply has to be a threshold somewhere where the definition stops making sense, so it's only applicable to those places where something like this is possible.
      • I don't exactly know what the "neighborhood" is defined as, but note how its volume (and as result, space that is to be cleared) rises with cube of orbital radius. At 200AU the hypothetical planets have 8,000,000 times more cubic kilometers of space to wipe than Earth does.

        • by Anonymous Coward

          Quantitative work has been done on how difficult it is to scatter crossing orbits and for other smaller bodies into a resonance, and the difficulty doesn't quite scale with volume, but scales with orbit diameter (or semi-major axis for elliptical orbits) to the (3/2) power, while also scaling with the square of the bodies's mass. So in that sense, moving Earth out to a distance of 200 AU would make it roughly 3000 times harder to scatter bodies out of the orbit. But by those estimates, Earth has almost 40

    • by Urkki ( 668283 )

      At that range, you have to wonder enough time has elapsed since the formation of the solar system for them to have "cleared the neighborhood" around their orbits.

      If they are detected by looking at how they herd the minor bodies in the outer solar system, then I think it is safe to say they are indeed planets.

    • Interesting point. Let's say a planet orbits the Sun once every 1000 years (Pluto's is almost 248 years). This means roughly 4.6 million planetary "years" from that planet's reference frame. Did Earth clear its orbital neighborhood in 4.6 million years? Probably not.

  • I hope I'm alive long enough for somebody to build probes that are fast and powerful enough to reach and map these places.

    The trouble with present technology, is that most rockets/spacecraft only have enough delta-V to take decades to get out there, and nowhere near enough to actually go into orbit when they get out there.

    Hazarding a guess, I would say that that'll only happen when somebody gets around to building nuclear-powered engines. The big question is: who's got the money and balls to pull it off?

    • I wonder what the fastest possible chemically-propelled-rocket probe is? If the probe was made small and compact to do little more than take photos and spectrographic analysis, how fast could the bugger be made to travel using existing rocket tech?

      If it records the pass-by data and sends it back later at a slower pace, somewhat like New Horizons, then it doesn't need that big of an antenna.

      • by stjobe ( 78285 ) on Saturday January 17, 2015 @05:52PM (#48840869) Homepage

        I wonder what the fastest possible chemically-propelled-rocket probe is? If the probe was made small and compact to do little more than take photos and spectrographic analysis, how fast could the bugger be made to travel using existing rocket tech?

        While not chemically-propelled, Freeman Dyson calculated while working on the Orion project [wikipedia.org] that one of those magnificent bastards could achieve 3.3% of the speed of light (0.03c, 10,000 km/s, or roughly 22 million kph - give or take a few hundred thousand mph - by firing a shaped-charge nuclear bomb behind it every three seconds for ten days straight.

        At that speed, Alpha Centauri is just 133 years away, and these ETNOs are really not much farther than down the road to the chemist.

        It's a shame that project never came to anything but a few chemical proof-of-concept scale tests.

        • by Tablizer ( 95088 )

          by firing a shaped-charge nuclear bomb behind it every three seconds for ten days straight.

          That's a lot of nukes.

          • by stjobe ( 78285 )

            Yep. 300,000 1-megaton yield nukes at 1 metric ton each.

            The proposed design had a departure mass of 400,000 tons, with a 50,000 ton payload.

      • > I wonder what the fastest possible chemically-propelled-rocket probe is?

        Slower than a Nuclear-ion probe. Nuclear in this case means a small nuclear reactor, say in the 1 MW power range. Plasma thrusters have an exhaust velocity of ~ 50 km/s, and it is reasonable to reach 3x exhaust velocity, thus 150 km/s. The mass ratio (propellant to empty mass) would be 20:1 in that case. For any kind of chemical rocket to reach that velocity, it would need a mass ratio of 10 trillion, which is seriously imprac

    • And are well understood.

      Short on balls to use them, though.

    • It's nowhere near impossible, it would just require a decent budget.

      First, not a single probe but a bunch of them, to cover more of the space. Of course not all at once, but a program of sending a new one every five years or so would be nice.
      Next, equip the probes with decent telescopes. Something like Hubble, maybe a little more on the budget side. The number of probes and the time would contribute to more coverage.
      And give them some surplus fuel. So that if something is discovered, a probe can be redirect

  • Nothing new (Score:1, Insightful)

    by Anonymous Coward

    Alf already predicted this http://alf.wikia.com/wiki/Alvin

  • Of course! (Score:3, Interesting)

    by __aaclcg7560 ( 824291 ) on Saturday January 17, 2015 @03:54PM (#48840311)
    This would explain why SPACE: 1999 [wikipedia.org] had the runaway Moon passing a planet outside the solar system in every episode. For all these years, I thought British SF TV was just weak in the science department.
  • They said back then that there is a massive "Planet X" that may orbit in the reverse direction from other planets.

    We know now that the universe is full of orphan planets, so it would hardly surprise me if there are many such planets randomly drifting toward stars.

  • If they're out there, they are cold and dark, and really really far away. As long as they stay there, it makes no difference to us.

Mathematics is the only science where one never knows what one is talking about nor whether what is said is true. -- Russell

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