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Destruction of Solar System by passing Star

  1. Sep 27, 2015 #1
    Suppose a star passed by our solar system. How close would it have to come before the orbits of planets was significantly and permanently perturbed? How close to cast a planet out of orbit? Let's say that that star is a cold neutron star, so we know its mass (1.5 solar masses) and don't have to worry about heat or gasses coming from it.
     
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  3. Sep 27, 2015 #2

    Bystander

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    "Permanently?" Anywhere in the observable universe. "Significantly?" What's "significant" to you?
     
  4. Sep 27, 2015 #3

    mfb

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    Some small multiple of the orbital radius, the number depends on the definition of "significantly" and details of the passing process. There are secondary effects as well: even if the neutron star leaves the orbit of Earth without significant changes, if Jupiter gets a completely new orbit this could disturb the orbit of Earth over the following millions of years.

    There are many online gravity simulators where you can test this yourself.
     
  5. Sep 28, 2015 #4
    What mfb said.
    As is, the Solar System is basically settled into a relatively stable state. Once you tweek a few orbits, even a little, it may go unstable for a while.
     
  6. Sep 28, 2015 #5
    The dynamics of multiple body systems is notoriously difficult to predict once it gets beyond four or so bodies.
    However it has been suggested, in my opinion reasonably, that the nearby passage of another star is a possible explanation for the present arrangement of the solar system's large outer planets,
    and also for the 'late heavy bombardment' event in which the smaller inner planets became subjected to a period of frequent collisions with other planetoids, asteroids, and comets.
    This in turn is a plausible explanation for anomalous states of some planets such as Uranus rotating on it's side relative to the solar plane, Venus rotating 'backwards', and maybe why the Earth acquired a single and such a relatively large Moon.
     
    Last edited: Sep 28, 2015
  7. Sep 29, 2015 #6

    Chronos

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    Cratering is not preserved on gas giants, so we have no cause to believe they were spared from the heavy bombardment period. Impacts during that time could have flipped a planet sideways [Uranus], upside down [Venus] or birthed a peculiarly large moon [earth].
     
  8. Sep 30, 2015 #7

    tony873004

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    Here comes Trouble. It's 1.5 solar masses and will pass 1.2 AU from the Sun in 2015.
    http://orbitsimulator.com/gravitySimulatorCloud/simulations/1443592405079_trouble.html

    Press the Play button [>] on the Time Step control to begin.
    Press "E" to edit the starting conditions. Choose the object named "Trouble" and change its starting position, velocity, and mass.
    Press "L" to see the names of the objects.

    And what are the odds of this?
    You can use this calculator: http://orbitsimulator.com/formulas/cse.html
    to determine that we can expect a 1.2 AU solar passage about once every 10 quadrillion years.
     
  9. Sep 30, 2015 #8

    Chronos

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    Do you have a credible source for what appears to be nothing more than another crackpot Niburu [planet X] story?
     
  10. Sep 30, 2015 #9

    mfb

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    The simulation seems to be centered at Sun, which leads to odd pseudo-trajectories for some planets. It looks like they accelerate away from both Sun and Trouble, where in reality Sun is accelerated.
    A credible source for a hypothetical scenario?

    It doesn't have to destroy the inner solar system. As an example, change the y-component of trouble's velocity to 36.something km (from 26.something). It will still pass closer than Jupiter, but the inner planets stay in (roughly) circular orbits.
     
  11. Sep 30, 2015 #10

    tony873004

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  12. Sep 30, 2015 #11
    Stars have already passed our star within the Oort Cloud of our solar system. The last one was ~70,000 years ago called Scholz's star (2MASS J07200325−0846499) and passed within 52,000 AU (0.25 parsecs; 0.82 light-years). Scholz's star is actually a binary system consisting of an M9.5 star and a T5 brown dwarf.

    There is also a 90% chance that HIP 85605 (2MASS J17293627+2439111) will pass within 8,200 AU to 41,100 AU (0.04 to 0.2 parsecs; 0.13 to 0.65 light-years) from the Sun within 240,000 to 470,000 years. It has not yet been determined whether HIP 85605 is a Type M or K star, and there is some dispute with the parallax measurement.

    While neither passage of either star system will perturb the orbits of the planets, they will perturb the orbits of Oort Cloud and possibly Kuiper Belt objects and that could ultimately have ramifications on the inner solar system in time. It may take a couple million years after the passage of these star systems, but the inner solar system could suddenly find themselves bombarded with comets.

    It is estimated that another solar system will pass within one light-year of Sol every 9 million years.
     
    Last edited: Sep 30, 2015
  13. Sep 30, 2015 #12
    Not immediately anyway. But then 10,000 or 100,000 years later, Jupiter, in its new orbit, has pumped up (or down) all of the inner planet's orbits hundreds of times. What about the asteroid belt - a new late,late heavy bombardment? Probably millions of years before it all settles down again, during which some stuff will get ejected from the system or move into new, stable orbits.
     
  14. Oct 2, 2015 #13
    Let us now when such a star is spotted. Then we can...do nothing at all about it.
     
  15. Oct 2, 2015 #14

    mfb

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    In the example, all outer planets escape. A likely result, as sun gets a significant velocity change - much larger than the orbital speed of the outer planets.

    The asteroid belt will be fun...
     
  16. Oct 2, 2015 #15

    tony873004

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