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Space

Our Early Solar System May Have Been Home To a Fifth Giant Planet 60

sciencehabit writes: A cluster of icy bodies in the same region as Pluto could be proof that our early solar system was home to a fifth giant planet, according to new research (abstract). That planet may have 'bumped' Neptune during its migration away from the sun 4 billion years ago, causing the ice giant to jump into its current orbit and scattering a cluster of its satellites into the Kuiper belt in the outer solar system.
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Our Early Solar System May Have Been Home To a Fifth Giant Planet

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  • by DoktorMidnight ( 3469647 ) on Tuesday August 11, 2015 @05:11PM (#50297165)
    Zecharia Sitchin was right along!
    • If we're naming a lost, Jupiter-sized planet on the edge of the solar system, I'm pulling for "Yuggoth" before "Nibiru".

  • by Anonymous Coward

    Maybe YOUR solar, system, you earthlings.

  • Nibiru

  • by PPH ( 736903 ) on Tuesday August 11, 2015 @05:46PM (#50297367)

    I hope it left a note on Neptune's windshield.

  • See http://www.sacred-texts.com/ea... [sacred-texts.com] Thus, the images that we see in the night sky are most likely on the firmament. We can never get there, just as "A11 work and no play makes Jack a dull boy" (A11 being short for Apollo 11, that is).
  • by H0p313ss ( 811249 ) on Tuesday August 11, 2015 @05:48PM (#50297379)

    It would be real nice if reporters could tell the difference between "suggests" and "proof"

    • I was thinking the same thing. Words like "proof" are almost always out of place when talking about new hypotheses. It's a good theory, but call the data what it is: evidence that supports the theory.

    • Why should reporters be held to a higher standard than the average Slashdotter?

    • It would be real nice if reporters could tell the difference between "suggests" and "proof"

      The heading should read: "Astronomers have found a set of parameters that could describe our current solar system (as could many others)".

    • It would be real nice if reporters could tell the difference between "suggests" and "proof"

      There is no proof in the real world. Only very thinly veiled suggestions.

  • by Rei ( 128717 ) on Tuesday August 11, 2015 @05:55PM (#50297429) Homepage

    Because things have been messing with bodies way far away from the sun. Take Sedna, for example. It's perihelion is 76 AU (Neptune's is about 31 AU from the sun, much to far to have an significant effect on Sedna). Sedna's apohelion is 936 AU. Very, very elliptical, and off-axis too - it clearly didn't form in this orbit from the sun's accretion disk, something has seriously messed with its orbit. But that couldn't have been something *close* to the sun, because then Sedna's orbit would have to come back close to it, aka, into the inner solar system. And Sedna is no little rock, it's 1000 kilometers in diameter - bigger than Ceres. For something to have thrown it into such an extreme orbit it had to be quite large, and not anywhere near where the large planets of our solar system are.

    So the question is.... what?

    It may seem an obvious assumption to think that if there were any more large planets in our solar system we'd have seen them - but it's actually not the case. By the data from WISE, we can rule out Jupiter-sized planets 26000 AU out, and Saturn-sized planets 10000 AU out. But there could still be multiple Earth-sized planets at only several hundred AU out - we really have no idea. It's just really hard to see things out there, the light they reflect from the sun is so weak.

    Another possibility is that stars have sometimes drifted by our stellar neighborhood close enough to play havoc with things. Potentially more interesting is the concept that far more common than stars roaming past our neighborhood, there could be roaming planets outnumbering star that occasionally pass through and disrupt or are even captured by our system.

    • So the question is.... what?

      This is obviously the result of a large celestial object passing through at near right angles to the plane of the star system. Probably a black hole.

    • by Anonymous Coward

      But that couldn't have been something *close* to the sun, because then Sedna's orbit would have to come back close to it, aka, into the inner solar system

      There are three-body processes that will move an perihelion with time, in exchange for eccentricity. In a larger multi-body system, that will interact with orbital resonance to sometimes cause things to drift and settle elsewhere. Considering how much movement there is of gas-giants in some models from such processes, it is possible to move something like Sedna's orbit away from its last close interaction.

      • by Rei ( 128717 )

        Indeed, that is possible - but not with the gas giants where they are today, the strength of the interaction is too little. A gas giant migrating inward from an area where it had been strongly interacting with Sedna to its present day area where it no longer is would be a possibility.

        That said, possibilities to explain the orbit of one single body in the outer solar system aren't enough, there's a lot of data that a model has to account for - other Sedna-like bodies (there's another one discovered with curi

        • by Rei ( 128717 )

          ** Corr: nearly identical perihelion, not aphelion. And the other body is 2012 VP113.

      • by Rei ( 128717 )

        It should also be noted that there is a "known unknown" issue related to what Kuiper objects are out there undiscovered - we know that we've only discovered a tiny fraction of them, and the further out we go, the smaller the fraction that have been discovered. And we've seen what sort of size distribution they follow thusfar. I've seen published calculations that suggest that based on what we've discovered thusfar and the percentage of bodies we believe we've discovered thusfar, an Earth-sized far outer pla

  • So the dwarf planets in the Kuiper belt could be old Neptune moons?

    • by TWX ( 665546 )
      That was my take on it too, or that they're from this otherwise unknown gas giant that's now gone. Hell, so by this measure Pluto might have formed as a moon and become a rogue planet due to gravitational disruption...
  • And our space faring civilization was founded from the remnants of that fifth planet.

  • But as plausible as the rogue planet theory as well. there is zero and I mean ZERO evidence. not even any mildly compelling observations. It's 100% wild speculation.

  • Isn't this what the Nemesis folks have been talking about?

  • TFA: "No one knows what became of the missing planet..."

    Maybe it's up Uranus.

  • A planet might have existed where the asteroid belt is between Mars and Jupiter. James P. Hogan did a series of novels of a planetary war that broke up the planet and the survivors colonized Earth. Nothing worse than being stuck between the king of gods and the god of war.
  • by anwyn ( 266338 ) on Wednesday August 12, 2015 @05:50AM (#50299771)
    How much energy is required to eject a Jupiter sized planet from the solar system? Where did this energy come from?
    • by Anonymous Coward

      To eject a planet you need to double the energy that it already has in its orbital speed. The energy comes from the orbital speed and/or gravitational potential energy of another planet.

      • by anwyn ( 266338 )
        So to get this old Jupiter sized planet ejected, you had to steal most of the orbital energy of 2 or 3 other Jupiter sized planets. Where are those planets now?
        • by Anonymous Coward

          No, to double x you need to add x, so you need to steal the orbital energy of exactly 1 other Jupiter-sized planet. BTW it's improper to start with a hypothetical question ("Jupiter sized planet"), and finish with a question about reality ("where are those planets now?"). The story only claims a fifth giant planet. To eject a Uranus-sized planet you only need to steal 1/22 of the orbital energy of a Jupiter-sized planet.

          • by Anonymous Coward

            Maybe a planet or two fell into the sun. Mighty big, the sun is. Deep too. Drop something in there, you won't see it again.

    • Re: (Score:2, Informative)

      by Anonymous Coward

      Two planets that pass too close to each other will disturb each others orbits, for example sending one outwards and the other inwards.

      When a spacecraft does this, it is called a slingshot maneuver or gravity assist, but due to the size differences, the spacecraft gets a huge change, and the planet gets a microscopic one.

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