50 billion year later,the sun will expand, the earth will gone

umm, ok. 

 I've seen this before on Facebook. It's not a solution.

The ISS will never carry nuclear bombs!

Current models suggest the asteriod will pass wide of the 'Keyhole' and miss Earth upon the return.
Even if it does, nuclear bombs aren't guaranteed to destroy the thing. That depends on the makeup of the asteroid!

At international conferences where planetary scientists discuss these proposals, there is general agreement that this would be a bad way to approach such a problem.

Forgetting for a moment the logistics of accomplishing it, what it creates is a great many more incoming chunks of asteroid, each of which would be at least slightly radioactive.

When this proposal was first put forward, studies showed that even if a significant amount of the original asteroid's mass missed Earth, the atmospheric heating effects of hundreds or thousands of relatively large (more than a few tons each) meteoroids entering the atmosphere together would be as bad as a single larger chunk.

While you'd think that having the smaller chunks more completely burn up before reaching the ground is a good thing, you must consider where all that heat ends up: in the atmosphere! That could be a very bad day, indeed.

There is no clear consensus as to how to approach these threats, other than that early identification is the primary goal. But there is general agreement that given enough time the best approach is some means of steering or nudging an incoming asteroid off course enough to ensure a miss.

You might find this interview with planetary scientist Jay Melosh interesting reading.

Good evening a8603103.

That's a funny old name.I guess your folks had a sense of humour.

Apophis featured on our news a few years ago & we were told that it would 'near miss'Earth.

Do you have credible proof that it will hit us? If so,where did you get that proof from?

 i heard of a theory to nudge asteroids off course by using lasers to make small detonations on the surface and change its direction slightly. with each detonation, it would get further and further off course. if this were possible, we could prevent them from ever coming near earth. it seems to me that this is a much safer course of action and with our current level of technology, it might not even be too far off from development.

I guess there are those who still seek a way to justify the continued existence of nuclear weapons as asteroid killers.  Putting these things into orbit is nonsense.  As was pointed out blowing up Apophis would be a really bad idea.  To put it in layman's terms we would simply be exchanging the form of our demise from that of a high powered rifle to that of a shotgun. The kinetic energy of this mass is not changed by this method.  Either way would most certainly mean a bad day all around.

At the present time the odds are miniscule that we will be harmed this time but follow the links listed above for some other ideas on how disaster of this type may be averted at some future date. 

L

Shady:

a bad coconut shell with gistrines in 4th post

RIP_Shadowfox's mention of lasers sounds like a good method to investigate.

I wonder what happend when you detonate a nuke near (e.g. a mile away) an asteroid.  Is there a "shockwave" in space from this?  Does the flux of radiation and particles change the direction of the asteroid appreciably?  Can it be nudged instead of blown up?  Obviously many factors must be considered - distance, velocity, composition, mass,... 

Gravity tug seems innovative too, but is useful only for small asteroids at large distances. 

Just my opinion, but I'd invest money on asteroid mitigation strategies rather than manned missions to the Moon or Mars.  Those bodies aren't going anywhere - they'll be there for us to explore later when we have cheaper rocket propulsion.

This will happen sooner - a few billion years.

Go out and find the book, "Death from the Skies" by Philip Plait. It will either help you to worry about way more stuff, or decide to just get on with life.

There is way more important stuff to worry about than things you can't do anything about. (right now) Personally I believe tha world governments won't tell us if we are about to be taken out by a really big asteroid. I truly doubt that the general public could handle it.

Bill

but why supernova can make a shockwave?

and i d better put a csar bomb to bomb it

proof here

http://www.youtube.com/watch?v=e4HCTcQ-IWA

a8603103:

50 billion year later,the sun will expand, the earth will gone

More like 5 billion...<poof> the earth will gone