How would you stop one?

Blow it up? Not really helpful.

Put an engine on it? Maybe a VASMIR with enough time, but then you have to power the VASMIR.

That is exactly what would happen.

A nuclear explosion is space would not re-direct an asteroid. Without atmosphere, a nuclear weapon is light/heat/radiation weapon. No "explosion", since almost no material to vaporize. It would create LOTS of radiant heat some things around a nuke will simply melt. It would have to be on the surface or under the surface, and vaporize rock. But the gasses would not be as directional and very inefficient.

A good analogy, gun powder lit on fire in a pile vs. contained in a pipe.

Meteor crater in Arizona was formed only about 50,000 years ago.

Wasn't that one pretty small though? I'm talkin' about a bigly one....then again, a golf ball size one hittin' yer noggin is gonna make ya say ouch :)

Hypothetically, at least according to one of our lab fellows and bomb designer/physicists, the photons (gamma/x rays) would heat and then vaporize or simply just ablate the material on the surface facing the bomb. The ejected used-to-be-asteroid gas would give a reaction force/impulse that would nudge the rock in a slightly different direction. Given enough time and distance you could steer it away from earth.

like all of the best ideas, it works out on paper...

160 feet (50 meters) across AND it was metallic. Supposed have lost 1/2 its mass before hitting the ground. Not tiny. The Dinosaur killer was 6 miles (10km) across.

Zhamanshin crater is about 10 times larger than Meteor Crater and occurred around 900,000 BC.

Most of the energy would be wasted. On earth, in the Atmosphere, the shock-wave keeps going.

The other issue is the size of warheads. We need them to exit earth gravity. Most of the REALLY BIG bombs weighed around 40,000 lbs (20 Tons).

The largest object we've sent outside earth gravity was the ExoMars Trace Gas Orbiter last year, and it was 10,000 (5 tons). This is similar to the MK-41, which was 25MT.

How to Stop a Killer Asteroid | DiscoverMagazine.com

Seems like you'd detonate a nuclear warhead by the asteroid, the radiation would vaporize part of the asteroid, and the reaction force from the gas would deflect the asteroid. The tiniest deflection would be enough. It might not have to be a terribly large warhead. The WW2 bombs weighed 5 tons. We can send a 5 ton payload into orbit, then a launch vehicle, and mate them in orbit.

We might not know the composition of the asteroid well enough to predict the exact deflection, but a miss is as good as a mile.

We might accidentally fragment the asteroid, but the fragments wouldn't impact Earth unless one of the fragments continued on the exact same course as the original asteroid, which seems unlikely. And if that fragment were significantly smaller than the original asteroid, then it would be more likely to burn up in the atmosphere or cause less damage on impact.

Seems like a reasonable thing to try.

And we'd want to have the launch vehicle and warhead ready now. Suppose a killer asteroid is discovered 3 years before impact. It might take a year to design, build and launch an interceptor, then it has to travel to meet the asteroid, which will by then be much closer to Earth - the asteroid will be traveling much faster than the interceptor - and a larger deflection will be needed. Better to have the interceptor orbiting the earth and ready to launch.

Granted that means a nuclear weapon in orbit. But the US, China and Russia could jointly build the interceptor, so that each nation would be confident there is only one such warhead there. A single orbiting warhead doesn't add that much risk to several thousand warheads already in missiles aimed at each other.

Nature will start over, probably with bees, that's the most logical place to start.

"We" can't agree on climate change and yet somehow we're going to get together on this? :(

Cockroaches....and Keef Richards :)

Were we to perfect an astroid destroyer/deflector....the day we put it in place, Yellowstone will beotch slap us silly humans just for fun :).

Getting a nuke into space isn't exactly safe, if something goes wrong on take off all of Florida gets a dirty bomb.

The next launch which had been scheduled for after the Challenger disaster in 1986 was to be a nuke powered military satellite. We would have lost more than a school teacher in that one.

We DID lose a LOT more than a school teacher in the Challenger disaster. She was just one of the 7 people on board.

I know that, but we didn't lose the whole state of Florida.

The Metro Times called it the most under reported news story of that year.

If we send nukes up into space, let it be from Russia or some far away island.

We don't "make up" asteroids. ;)

When that one goes, it's gonna be lights out for all of us and global warming will be reversed for the next several thousand years. And don't forget the Cascadia Subduction Zone. Scary stuff.

Found it:

http://forums.pelicanparts.com/uploa...1492526013.jpg

Yeah, but that one only goes boom about every 630,000 years.

It's been 630,000 years since that last one so we have plenty of time wait what?

I have no doubt we could figure out a way to do it... we put a man on the moon and robots on Mars and stuff like that.

Question is can we stop trying to kill each other long enough to make it happen (and divert all the money we invest in doing all that killin).

I heard on the radio this morning (so it must be true) it would take 3-5 years to plan something like this.