what would be your Idea of defense if a asteroid were to hit earth

Chances are that any asteroid heading for earth will not be noticed until its too late to do anything about it except hope for the best.

Im not sure about this but wouldnt it be difficult to intercept an asteroid. The speed it would be travelling towards us would mean that to land anything on it you would have to get behind it and catch it up to match its speed otherwise they would fly by eachother. that would take a lot of fuel, speed and time.

Blowing it up would send millions of fragments our way and into solar orbit presenting more of a threat.

Therefore the ONLY sensible option in my opinion would be to deflect it with an explosion or dense object. we would have to have a lot of information about the asteroid though otherwise we might use too much or too little of an explosion or collision.

You don't really have to worry about how fast it's going. If explosives are involved, you just place them in its path and let the rock run into them.

How effective would a nuke be if the asteroid is traveling towards the missile at 50,000mph? At those speeds wouldn't the asteroid just pass straight through the explosion before its shock wave could take effect? How fast does a nuke's explosion travel outwards and with how much force? I would imagine you would have to set off the bomb at the same speed at which the asteroid is traveling, probably from its surface, or near it for a chance at deflection. I doubt a head on collision with a nuclear explosion would have much effect and I bet trying to time it exactly would be very difficult at 50,000mph. It would be harder than trying to deflect a bullet coming towards you with a grenade.

The way I see it is that we can deflect it with mass or energy. If we try and hit it with mass, then we would need something of the same mass traveling at the same speeds, otherwise it would probably just bounce off. This might deflect it if the asteroid is solid enough to take the impact. I don't know where we would get something the size of an asteroid to fling towards it.

Energy is a better option, but where do you get enough energy to effect a 5 mile wide rock traveling at 50,000mph. You could use explosions, but I would think you would need 1 very big one, or lots of very well timed smaller ones. I don't think nukes qualify as big ones or even small ones. You could use the suns energy, but you would have to focus it with large mirrors into a powerful laser.

What about sonics? Could you create a resonate sound frequency directed towards the asteroid adjusted perfectly so that the asteroid vibrates itself to dust?

Whatever it is, I believe we have much better odds if we have time to get close to it and study it. If our only option is to hit it head on, the I don't think we have the firepower to affect its trajectory.

Originally posted by fiftyfifty
Chances are that any asteroid heading for earth will not be noticed until its too late to do anything about it except hope for the best.

Which is why I proposed above that we set out to deflect and exploit all NEO's we detect. The earlier we start, the less chance we'll get blindsided.

Im not sure about this but wouldnt it be difficult to intercept an asteroid.

We've managed to intercept a comet and land a probe.

Blowing it up would send millions of fragments our way and into solar orbit presenting more of a threat.

You need to know the composition first. If it were a loosely jumbled pile of rocks then a directional charge to split it up and additional nukes strategically placed on the asteroid before the split takes place will be detonated in sequence to adjust their course the 1% needed to swing them into a completely harmless orbit.

If it's a solid piece, then the best way would be to simply change the albedo of the object.

Therefore the ONLY sensible option in my opinion would be to deflect it with an explosion or dense object. we would have to have a lot of information about the asteroid though otherwise we might use too much or too little of an explosion or collision.

There isn't only one sensible course of action to take. This is a very narrow minded view. As I said above, it's all about the composition of the NEO.

Originally posted by Toasty
How effective would a nuke be if the asteroid is traveling towards the missile at 50,000mph?

Placed on or within the asteroid, a Nuke can do wonders. The Armageddon approach is actually quite feasible. Though this would only be on certain asteroid types.

What about sonics? Could you create a resonate sound frequency directed towards the asteroid adjusted perfectly so that the asteroid vibrates itself to dust?

There is no sound in space. No atmosphere = No sound!

There is no sound in space. No atmosphere = No sound!

Ha i forgot about that little fact duh!

Placed on or within the asteroid, a Nuke can do wonders. The Armageddon approach is actually quite feasible. Though this would only be on certain asteroid types.

Probably not a good idea to use the movie Armageddon as a scientific reference, check out bad astronomy's review of it:
www.badastronomy.com...

The option space.com seem to be pushing is a nuke in close proximity.
www.space.com...
Its not the explosion that pushes the asteroid, but the vaporising material being shot from its surface.

In all honesty...
With the whole mess on the earth as it is now, the corruption, control, etc....Im not really at concern with anything from outside of the world, it could only benefit us.

Perhaps an asteroid would help knock some sense into us (those that survive...) or rather let the process of evolution begin again on earth. (back to the beginning, oh well)

If we could live at peace and harmony, still the chances of truly being hit from an asteroid that could do damage...slim (but what do I know...types this as huge asteroid draws closer to window. )

Peace

dAlen

The movie science behind Armageddon itself was flawed. All movie science is flawed, but the overall concept CAN WORK depending upon the composition of the Near Earth Object(NEO)

Your animation clearly shows an explosion taking place just in front of the asteroid. That asteroid also looks to be one solid chunk. Deflecting something like that with a Nuke would be idiotic. I've stated many times now, that our response will depend on the composition of the NEO.

I'm not interested in solely deflecting asteroid and Comets that are on a direct collision course, I want us to deflect anything that comes within 0.1 Au of us into a harmless or even possibly useful orbit.

I've mentioned using a Laser along with Changing the Albedo(reflectivity) of mudballs. Lasers for Iceballs. White Paint/Solar Sail for solid asteroids and nukes for jumbles of rocks that are only held together by their own gravity and nothing else. Not all NEOs are the same so no two NEOs will have an identical response. A solid titanium asteroid will definitely get billions poured into it's "redirection" to a more useful orbit(new moon anyone? ).

Point being, is that there are ways to defend earth if we start now. Going to the Moon and Mars will help but it won't help as much as a dedicated worldwide effort.

Originally posted by sardion2000

Im not sure about this but wouldnt it be difficult to intercept an asteroid.

We've managed to intercept a comet and land a probe.

Intercepting a comet is totally different becaue we knew it's orbit and it was heading directly towards us. We actually waited until it was at its closest point passing earth and met it at an angle, if a NEOs trajectory was Earth at 50,000mph we would have to approach it at speed to get to it in plenty of time making it inpossible to decelerate, stop and head back towards earth at 50,000 mph

Oops i dont know what i did there ^^^ but thats my post

There is another way of altering the trajectory of an in bound object.

We frame drag space (warping) just ahead of the object using the Lense-Thirring Effect.

A simple physical interpretation of the Lense thirring effect based on EMQG Theory

Note: The paper talks of Gravitons - LQG updates this and negates the need for gravitons, since gravity is caused by space density / surface area.

This would need a significant mass and the only way currently to produce this is with some form of particle accelerator....

This would however also require significant sustainable power to create the mass and so is unworkable with present technology. However, in the near future this would be an ideal way of controling the direction of any mass travling through space-time.

If you want to know more about Frame dragging or Lense thirring, let me know.

All the best,

NeoN HaZe.

[edit on 3-1-2007 by Neon Haze]

I would send a team of wildcatters to the asteroid to drill down and lay and nuclear warhead inside the asteroid. Then one of the guys would have to become the hero and stay behind to detonate the nuke just befored it passed the "If it passes this line we're screwed" line.