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Apophis to impact earth in 2036?

  1. Jan 5, 2006 #1

    Ivan Seeking

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    This is probably the third time that I have heard or read conflicting reports on this.

    http://www.rutlandherald.com/apps/pbcs.dll/article?AID=/20060104/NEWS/601040303/1039



    http://www.earthsky.org/shows/astrophysics_interviews.php?id=49241
     
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  3. Jan 5, 2006 #2

    Pengwuino

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    So.... call me stupid (don't call me stupid), but why again can't we just send up a couple of nukes to at least move or breakup these things? I don't really see what could be worse then something hitting earth and whiping out all of mankind....
     
  4. Jan 5, 2006 #3

    Ivan Seeking

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    Simulations indicate that in many cases we could just make things worse by breaking it up, or it may have too little influence to be of use, but a few people are exploring all sorts of ways to deflect asteroids.
     
    Last edited: Jan 5, 2006
  5. Jan 5, 2006 #4

    Pengwuino

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    Well what would "worse" be? Is the planet going to be destroyed twice as bad? :P

    How big does something have to be until anything we do starts having "little to no influence" with current technology?
     
  6. Jan 5, 2006 #5

    Ivan Seeking

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    Apparently one big object can be a better option than a bunch of little ones - I assume because the latter affects a larger area.
     
  7. Jan 5, 2006 #6

    russ_watters

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    Same theory as with nuclear weapons (why we use MIRVs instead of just really really big bombs) - doubling the energy does not double the damage because so much of the energy goes into digging a big hole. Since that area has already been completely destroyed, digging a biger hole there isn't going to destroy it any worse. More objects means smaller craters but far more widespread damage. But of course, a lot depends on where they hit.

    Hypothetically, if you had a big asteroid that was going to turn Europe into a big crater, the US would probably be OK - but splitting it in half might cause one half to hit Europe and the other the US - turning both into only slightly smaller craters.
     
    Last edited: Jan 5, 2006
  8. Jan 5, 2006 #7

    Pengwuino

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    Well i was thinking... if the objects are smaller, would friction be able to reduce the pieces sizes more then if it were one huge object..
     
  9. Jan 5, 2006 #8

    russ_watters

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    Yes, but you'd really have to shatter it. The pieces would need to be a tiny fraction of the initial size. For an impact at 30,000 mph, the atmosphere doesn't take off as much as you may expect.
     
  10. Jan 5, 2006 #9

    Janus

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    While Apophis will pass close to the Earth in 2029, There is no chance of collision at this time, but if, during that close approach, it passes through a small window known as the "keyhole" it will be put in an orbit that will cause a collision in 2036.

    Now, the keyhole is much smaller target than the Earth so if we needed to deflect Apophis to prevent said collision, our best bet is to deflect it prior to 2029 such that it misses the keyhole.
     
  11. Jan 6, 2006 #10

    Chronos

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    Predicting asteroid orbits is frightfully complicated. Talk about n-body simulations. The small mass makes it susceptible to the slightlest tugs of other, more massive bodies in the solar system.

    As others have noted, blasting it to pieces is not a good solution - unless the pieces are small enough to burn up in the atmosphere. Think of it as a 00 shotgun blast compared to a rifle slug. Deflecting the large mass so it lands in an ocean [or misses the earth entirely] is a much better bet.
     
  12. Jan 6, 2006 #11

    Janus

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    An ocean strike could be worse than a land strike. A land strike would be localized, an ocean strike could trigger a tsunami that would affect large areas of coastline.
     
  13. Jan 6, 2006 #12

    D H

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    An ocean strike would be much worse than a land strike. Nearly all of the energy from an ocean strike is converted into water vapor, while a significant portion of the energy from a land strike would be radiated into space. The tsunami from an ocean strike is just a harbinger of the bigger problems that will ensue.

    The nuclear option is not so bad so long as the explosion is used to change the asteroid's orbit rather than break it into a lot of little pieces. However, we need to know a lot more regarding the asteroid's composition to determine if the nuclear option is viable. Some asteroids are tight, compact masses. Others are already a conglomerate of little pieces that are loosely held together by the asteroid's weak gravity. Exploding a nuke near a tight, compact mass won't do a whole lot of damage but it will change the orbit. On the other hand, blowing up a dirt ball will disperse the dirt ball, thereby increasing the chances of a collision.
     
  14. Jan 6, 2006 #13
    How about manoeuvring a satelite to land on it or attach to it and then giving it a good braking with a rocket engine to get it into a much lower orbit around the sun. Then it would never get close to Earth again.

    And better do it as soon as possible while we still have the technology and the fossil fuel.
     
  15. Jan 6, 2006 #14

    Art

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    Here's a new approach NASA are exploring in handling asteroids;
    http://www.universetoday.com/am/publish/podcast_gravity_tractor_beam.html
     
    Last edited: Jan 6, 2006
  16. Jan 6, 2006 #15
    http://en.wikipedia.org/wiki/2004_MN4#Possible_impact_effects

    Over four times the destruction of the Krakatoa eruption! That’s a lot of energy and destruction, but not quite life threatening to mankind. I’m not sure it would make much difference on land or ocean, as the dust would surely effect climate all around the world. Though I would probably still say it would be worse if it impacted the ocean.
     
  17. Jan 6, 2006 #16
    It's only about the size of a single antimatter car bomb. . . .
    :biggrin:
     
  18. Jan 7, 2006 #17

    Chronos

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    A tsunami would only affect coastal regions, a land strike would raise a dust cloud that would play h*ll with the atmosphere for years. Earth would recover much more rapidly from an ocean strike.
     
  19. Jan 7, 2006 #18
    I am pretty certain that the best is yet to come?

    It will be a "non-destructive" application that will be the best.

    Maybe a 'deflection' devise can be implimented, if enough is known about the Asteroids structure and density, a number of low-energy nuclear devises could , in theory be used to induce "shock-wave", non-destructive energy fronts? that cause the Asteroid to stray from its Earthbound course.

    If there is a high metallicity content on the asteroid, there are, again "in theory", a good chance that a device can be made to dump a large "electrical-charge" or "magnetic-field" upon the Asteroid, if one can get the knowledge needed at an early stage?
     
  20. Jan 8, 2006 #19

    tony873004

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    Would it be more correct to say that the small mass makes it more susceptible to forces such as solar radiation pressure, solar wind, and the Yarkovsky effect? The more massive bodies in the solar system will not tug it harder simply because of its low mass. Due strictly to gravity, it will accelerate the same whether it's a piece of microscopic dust, or a full planet for the same reason that a big rock and a small rock drop to the ground at the same rate.
    Regarding blasting it into a million pieces, I don't see why that would be a bad idea unless we did it only a few days before impact. Sure, it would be no better to be blasted with a million small pieces with a combined mass of one big piece. But why would we get blasted by all 1 million pieces? Why would the asteroid fragment into a million pieces and then travel through space like science fiction asteroid field. The pieces will not have enough combined gravity to pull themselves together again into a single asteroid. So they will continue to spread apart. Even if the individual pieces were travelling 1 meter per second with respect to each other, in only 150 days, the average spacing between them would exceed 1 Earth diameter. Earth may just simply cruise through the open space in the diffuse debris belt without getting hit at all, or just getting hit by a few pieces of the original million.
     
  21. Jan 8, 2006 #20

    Ivan Seeking

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    From an previous report. I still don't know the proper time line on all of this or the current odds that it will strike. I assume that a couple of news reports were inaccurate, and also that a few astronomers who commented on this didn't know about the potential for a strike in 2036 and were speaking to the 2029 encounter.

    http://www.space.com/news/051103_asteroid_apophis.html
     
    Last edited: Jan 8, 2006
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