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Erosion of comet with Dark Matter.

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  1. Jul 27, 2012 #1
    If there is Dark Matter in the solar system, the erosion of comet with Dark Matter will be happen? A comet's main component is water, water has many nucleus per unit volume. and comet speed is very high. So. comet has high collision frequency with Dark Matter per time. Total energy for the erosion consists of the solar radiation, solar ion erosion and the erosion with Dark Matter. Is this concept wrong?
     
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  3. Jul 27, 2012 #2

    DaveC426913

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    Well, dark matter doesn't interact with regular matter, except via gravity. Any dark matter in the SS will pass right though the comet.
     
  4. Jul 27, 2012 #3
    How we think about detection it in the underground instrument? Might we belive this rule(time × measurable DM colliding frequency with the instrument )? If this rule is suitable, comet would also collide with measurable DM.
     
  5. Jul 27, 2012 #4

    DaveC426913

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    For your detection idea to work, it would have to be enough erosion to take a measurement.

    In this article, they mention an experiment with a whopping 67 collisions that might be candidates. Optimistically that's 67 molecules bumped out of place.
    http://en.wikipedia.org/wiki/Dark_matter#Direct_detection_experiments

    How would you know if a comet massing a few trillions of tons had collided with 67 dark matter particles?
     
    Last edited: Jul 27, 2012
  6. Jul 27, 2012 #5

    Drakkith

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    But this would not cause erosion on a significant enough scale to alter the comet even after billions of years.
     
  7. Jul 27, 2012 #6
    Have we never seen a comet which has a tail far away from the sun?
     
  8. Jul 27, 2012 #7

    phinds

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    What does that have to do with anything? What are you really asking?
     
  9. Jul 27, 2012 #8
    To make tail, sufficient energy must be supplied for evaporation or sublimation. The source of the energy, we think, is solar radiation energy, solar ion enrgy . But, we are far away from the sun. The energy is very low.
     
  10. Jul 27, 2012 #9

    DaveC426913

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    Ah. You are asking if we have ever spotted a comet that is far from the sun and has a tail.

    Probably not.

    But, as you can judge by the other responses to this thread, if we did see such a thing, it sure wouldn't be caused by dark matter. 67 molecules does not a tail make.
     
  11. Jul 27, 2012 #10

    Drakkith

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    I don't believe we have. And if we do see one, the tail will not be because of dark matter, it interacts far too weakly with normal matter for this to happen.
     
  12. Jul 27, 2012 #11
    One of the fast moving icy objects is Saturn's moon Enceladus. I am curious , it's polar region water vapor eruption. Some researchers say "it's electromagnetic phenomena".
    But it's eruption speed is too high. The water is erupted from the deep underground.
     
  13. Jul 27, 2012 #12

    DaveC426913

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    So?

    You are ignoring everything we've been saying.

    Dark matter does not interact with normal matter to any detectable degree beyond our best efforts under highly controlled and closely observed tests.

    I ask again: do you think 67 molecules bumped out of place can possibly be the cause for any of the phenomena you are trying to explain?
     
  14. Jul 27, 2012 #13
    Sorry, I only think fast moving increases the collision frequency per time. But, standstill collision frequency is too low.
     
  15. Jul 27, 2012 #14

    Drakkith

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    The solar system is moving in an orbit around the center of the galaxy at about 220 km/s. This is 10 times faster than Mars orbits the Sun, and since orbital velocity is directly related to distance from the Sun, the vast majority of the time a comet exists it is moving far below this speed. (The average orbital speed of Neptune is only 5.43 km/s, and many comets have part of their orbits beyond Neptune)
    So we are always moving at a high velocity relative to any dark matter in the galaxy.
     
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