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

I would like people to tell if they had Milatary resourses how they would try to some how stop a 2.5 km astroid from hiting earth.

Remember a astroid is low density so a comon missle will go through.

My idea is a .5 gigton nuke with purpolsion and opening flaps that open in the center of the astroid.
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Edit for spelling in title

[edit on 21/12/06 by masqua]

Despite it's in Space, I would choose an air burst detonation, as many as possible simultaneously. I'm not a physicist or aerospace engineer, but I feel that the combined force of so many massive explosions in the face of the object would change its course. But what do I know.

i think changing its coarse would be harder than blowing it up. Blowing it up is also hard cause a shock wave can't travel through nothing ness.

Originally posted by ghost00
Remember a astroid is low density so a comon missle will go through.

this is not neccesarily true...some are porous, others are jumbles of broken rock and yet others are almost pure iron or nickle.

www.psrd.hawaii.edu...

They find that the porosity of meteorites ranges from 5 to 35%. The porosity is in the form of cracks and spaces between mineral grains. Carbonaceous chondrites, which are dark rocks that contain carbon compounds (including organic chemicals) and water-bearing minerals, have porosities between 15% to 35%. In contrast, ordinary chondrites, which do not contain carbon compounds or water, have porosities of about 10%. Stony-iron meteorites have porosities of only about 5% and iron meteorites have essentially no porosity.

The nuke you mentioned might work for one asteroid, but cause problems with another...

www.space.com...

An asteroid is heading for Earth. With just days to go before the collision a beefed-up space shuttle is sent to intercept it. A brave team of astronauts and oil-rig workers drills deep into the space rock, plants a nuclear bomb and blows it in two. The two halves fly apart and miss the Earth.

Dream on!

The idea of blowing up an asteroid makes for good movie scripts, but is not the way to do it in the real universe. Many of the fragments would remain on a collision course and like the blast from a shotgun; the fragments can do up to ten times as much damage as the original, intact object.

In any case, Erik Asphaug from the University of Southern California has modeled "rubble-pile" asteroids and finds that blowing them up with bombs may be much more difficult than with asteroids made of solid rock. It is a bit like the difference between hitting a sandbag and a solid sandstone block with a sledgehammer -- the sandbag absorbs the impact with little disruption but the sandstone block shatters.

Click the above link for more on the idea of nuking (which IS being considered)

If it was a solid mass, I'd hit it with a massive conventional explosive. It would split into a lot of smaller pieces, which would increase the surface area exposed to the air when the pieces went through the atmosphere. This would result in more air resistance and more vaporization of the pieces. With luck, perhaps the pieces would be vaporized down to the point where the damage caused wouldn't result in mass destruction.

If it was extremely low density, perhaps something equivalent to a grenade full of shrapnel might blow it apart, if you could time the explosion just so. Then the air resistance would work as above. A conventional explosive might work too, if you could set it off at the right time, too. If it was low density, it might vaproize easier on its own without interference, as well.

Solid Mass:
Change it's reflective properties years before it's projected to even come near. Good old white paint will do wonders. Or I guess you could do something a bit more high tech if you have some time to spare. Nukes seem like a last ditched if all else fails type of solution. I believe we should have a program in place that will nudge asteroids classified as NEO(near earth object) at certain times in it's orbital path, then it should be nudged into a safer orbit. Perhaps if it's made of the right stuff that is, nudge it inti a collision course with mars or something just to see what would happen.

Jumble of rocks:
Find the weak spot and hit it with directional charges until it fractures. Adjust for the trajectories of the hopefully more solid pieces and nuke em to submission. Place a nuke to send them all flying out of the solar system. If multiple nukes are needed, use them!

Ice/Mudballs:
More tricky. Best bet here would be a combination of changing the albedo of the object and using a laser. We should be careful to make sure that it arrives around Mars orbit or a collision with mars. Whichever is most feasible.

[edit on 22-12-2006 by sardion2000]

you could have my origanil idea of nuke with flaps so it goes in the astroid but when it blows apart have a mine wall setup so it destroys the rest of the astroid in space. When the left over hits earth it burns up.

Originally posted by sardion2000
Solid Mass:
Change it's reflective properties years before it's projected to even come near. Good old white paint will do wonders.

Again you hit the nail on the head.

Despite the size and mass, it is relatively easy to change the solar orbital trajectory of an asteroid.

A change of just 1 degree at enough distance will do.

I'm all for the solar sail mechanic. Essentially you send a probe to attach itself to the asteroid surface, then it deploys a solar sail, the direction of the sail could easily be controlled from earth. This sail could be used to change the trajectory of the asteroid.

Nut shell we use the solar wind as a kind of wind break. Though you would have to come up with some way of ensuring the sail remained in the position you wanted it since the asteroid would be spinning.

But White paint would also have a similar effect, though applying it may be an issue.

This kind of intelligent thought makes me wonder what your occupation is.

All the best and a very merry Xmas!!

NeoN HaZe.

[edit on 22-12-2006 by Neon Haze]

That would be cool with the solar sails and stuff. Another thing is instead of making a space ship you could have probes that attach to a astroid and then open solar sails and you could hallow out the astroid then make it air tight and set up base in it.

How exactly does White Paint change the trajectory? I'm not being cynical but honestly curious, change in core temperature or what? Now I wanna know!

White paint will reflect light thus causeing it to act like a huge solar sail. The problem is in applying the paint in a vacuam.

I thought that solar sails functioned off of solar wind, which was completely separate from reflecting light?

Why not just...
bend over... seriously though nuke the sucker

you know what, this is a great idea for a thread-- props to the OP. This is an issue our societies will almost definitely face in the future, whether in ten years or a thousand.

i like the idea of melting or diverting the thing better than that of blowing it apart; even if we do succeed in blasting it into pieces, these pieces could very well remain large enough to do significant damage, but they would be spread across the surface of the earth.

could we build a laser capable of transmitting enough heat energy over a great enough distance to disintegrate an Earthbound comet? this would probably require a huge amount of power... who will provide it? i'm thinking the ITER fusion reactor could do the job, if nothing else.

but then we're left with the problem of denser objects. once again, the idea of blasting the object into smaller pieces doesn't really appeal to me... so how could we divert it?

what about a very large rail-gun, constructed Earthside, designed to deliver a mass of dense material at an oblique angle into the asteroid with enough kinetic energy to knock it off course? this sounds simpler than the delicate operation of landing anything on the surface of the NEO, and it could be reused in the event of future asteroid threats. sort of a planetary defense weapon.

these are just my thoughts... it's been interesting reading all of yours', and i hope to see more of them. once again, this is a great thread

It is a great topic, The Parallelogram, and I was glad to see someone bring it up as well. There will be many occasions in the future of mankind where these objects will be a concern.

Not only because of the danger they pose...that is our present and past...but in our future, asteroids will be a 'Godsend' because they hold so much value.

I saw a website somewhere recently (I'll have to search for it again) which goes into detail about the mining opportunity these asteroids and comets present. How about capturing comets for their water content...or mining asteroids for their metals so that they can be used to fabricate Starships on lunar bases?

Think that's far-fetched? Maybe so...but I predict that someday humanity will be searching our solar system for valuable chunks of space debris.

my idea of defense would be lots of bomb shelters and artillery to shoot them out of the sky.

In my astronomy lecture, we came across a similar question. Oddly enough, my professor said that "blowing up" the asteroid would not be effective, because due to its gravity, it would just pull itself back together again.

My solution would be to implement a laser strong enough at breaking the asteroid into smaller pieces, where it would burn up when it entered Earth's atmosphere.

Originally posted by Baphomet79
I thought that solar sails functioned off of solar wind, which was completely separate from reflecting light?

en.wikipedia.org...

Another false claim is that solar sails capture energy primarily from the "solar wind": high speed charged particles emitted from the sun. These particles would impart a small amount of momentum upon striking the sail, but this effect would be small compared to the force due to radiation pressure from light reflected from the sail. The force due to light pressure is about 100 times as strong as that due to solar wind.

Hope that answers your question.

science.howstuffworks.com...

NASA researchers have found that at 1 astronomical unit (AU), which is the distance from the sun to Earth, equal to 93 million miles (150 million km), sunlight can produce about 1.4 kilowatts (kw) of power. If you take 1.4 kw and divide it by the speed of light, you would find that the force exerted by the sun is about 9 newtons (N)/square mile (i.e., 2 lb/km2 or .78 lb/mi2).

[edit on 22-12-2006 by sardion2000]

there was a great doc' on the other night, about 3 weeks ago on the history channel or discovery.

it showed the earth getting barraged by a comet/asteroid that broke apart in the atmosphere and how much MORE destructive it was due to the multiple points of fiery mass now covering a huge area of earth. enough coverage for thousands of miles.

they attributed an incident like this that caused one of the 3 major mass extinctions in the past. they found a staggering amount of iridium - and other off-world elements that cover a HUGE area on earth's face.

i would opt for pushing the entity out of range, and not blowing it to bits.

i would probably..like have THE WORLD work together on developing a type of group missiles that don't explode on impact, but like launch them all simutaneouly and have it fly up the asteroid and attach itself and "dig" into the asteroid kind of like the tomatoe thing that sewers put their pins in, but like have the missiles all over it evenly and inside the tip part that "dig'ed" into the asteriod surface, have some type of explosive that isn't really too big.

just enough to grab a good chunk of the asteroid that it blew up and then from that broken tip, a kind of secondary rocket would "pull+lift" parts of the asteroid everywhich way, and directs the larger piece of the asteroids away from our planet.


a lot of words..lol, i would draw it..but mspaint isn't gonna do much justice for it lol.

DANG! only if like darpa or something hit me up..i'd give a hand in the idea lol