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I Defending the Earth from meteors using lasers

  1. Mar 20, 2017 #1
    Hello all. I am new here.

    I have an idea about defending the Earth from meteors using laser beams. I thought about using chemical lasers to burn the meteors.

    The first phase is that we use gas lasers if possible to create plasma by heating the gas and to use that plasma beam to strike at the meteor before it enters the lower atmosphere. The end result of this would be that the meteor would be burned. Now the second phase.

    For this idea, we would need many chemical lasers in many areas. But some would be located on satellites. Those on the satellites would target the far-Earth side of the meteor so that both sides would simultaneously burn.

    On this forum there are many professional physicists so I am interested to see what they think about this, looking at it from physics perspective.
  2. jcsd
  3. Mar 20, 2017 #2
    Conceptually the idea is not impossible.
    The trouble is that lasers powerful enough to accomplish this would require a power source equivalent to hundreds of nuclear power stations.
  4. Mar 20, 2017 #3
    Your idea would be a lot more interesting if it came with a cost proposal.
  5. Mar 20, 2017 #4
    If we advance enough, we might be able to store energy. I know we will not be able to keep it forever, but we might be able to make the energy circulate and we might be able to harvest solar energy using panels and store them or use nuclear energy.
  6. Mar 20, 2017 #5
    I think it is more important to save the Earth than to save money.
  7. Mar 20, 2017 #6
    That would be especially important if your method was the only one available.
  8. Mar 20, 2017 #7
    Is it possible to turn gas in the laser into plasma by heating?
  9. Mar 20, 2017 #8
  10. Mar 20, 2017 #9
  11. Mar 20, 2017 #10
  12. Mar 20, 2017 #11

    Vanadium 50

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    It doesn't seem that way to me. It seems to me that having them point out problems is making you unhappy.
  13. Mar 20, 2017 #12
    That's not really how we do things here on earth.
  14. Mar 21, 2017 #13
    You are thinking wrong. I want to discuss this with everyone,
  15. Mar 21, 2017 #14
    Producing that amount of energy and releasing it more or less instantly is definitely a big problem in itself.
    It also has secondary consequences in that unless the conductors used to carry the current are supercooled they will probably vaporize themselves.
    Supercoooling thousands of tons of electrical conductors requires even more energy if it can be done at all.
    Then you have the problem of the atmosphere; a fair amount of your hyperlaser energy will used up in ionising the air before it gets to the target.
  16. Mar 21, 2017 #15


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    Try comparing the cost of your proposal to the cost of simply nudging the asteroid out of the way so that it misses the Earth. If you start soon enough, only a very small push is sufficient to make it miss the Earth.
  17. Mar 21, 2017 #16
    What if the asteroid is big enough that nuclear bombs cannot save us?
  18. Mar 21, 2017 #17
    If it's that big, we should have sufficient time in spotting it and giving it a nudge. Nuclear explosives could cause issues with debris
  19. Mar 21, 2017 #18
    "Small" asteroids (say, below 50m) are not dangerous enough to bother - they can do only localized damage, not regional or global scale.

    Asteroids larger than that are too massive to nudge away with laser evaporation (with today's technology).

    Technology is going to progress, but ALL technology is going to progress, not only laser tech. With the possibility of heavier payloads being sent to incoming asteroids, and better guidance, it's more practical to send multiple multi-megaton nukes than building multi-terawatt lasers. (Also, for one, I object to anyone *having* multi-terawatt laser in Earth orbit!!!)
  20. Mar 21, 2017 #19


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    You seem to think that "burning" meteors (whatever that means) would make them simply vanish. What you will probably get is something coming at Earth with even more energy than it started with.
  21. Mar 21, 2017 #20
    Yeah that sure could be a problem if it was deployed for regular warfare purposes.
    Vaporizing an incoming large meteor is on the same scale as vaporizing a city.
    Then again it might make fantastic projects like lightsail probes to other nearby stars realisible.
    Last edited: Mar 21, 2017
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