Instead try to slow down/speed up earths by 1 meters/hour or maybe even 0.1 meters/hour
In time distends felled behind/gained will be enough to avoid impact by asteroid.

So when slowed down/speed up enough, Speed it up/slow it down back the same way,
by then earth will be moved from the asteroids path, and we won’t feel the smallest change in earths orbit.

But is it possible?
I don’t know maybe with some precise nuclear explosion

Instead try to slow down or speed up earths speed by 1 meters/hour or maybe even 0.1 meters/hour
In time distends felled behind will be enough to avoid impact by asteroid.

So when speed/slowed down enough Slow/speed it back up the same way, by then earth will be moved from the asteroids path and we wont feel the smallest change in earths orbit.

But is it possible?
I don’t know maybe with some precise nuclear explosion

By the time Apophis passes close to Earth in 2029 we should have the ability to engineer a way for it to go into orbit around the Earth/Moon system.

What a wonderful opportunity!

YOU GET THE TRICORDER, I'LL GRAB THE WALLET

Nobody has been able to sustain a fusion reaction.

When you have connected the cable from the ship to the rock and since you have matched relative velocity, why not use the ship's thrusters to pull on the anchored cable and change the direction of the asteroid.

Joe.

Just match relative velocities, slide up beside it like you were going to do a flyby, and then firmly connect a cable from ship to rock.

In principle, you can orbit anything, if your mass is significantly lower than the one of the thing you're orbiting and your velocity and distance are the right ones. If you're a particle of dust, you may be able to orbit an astronaut, for instance.

Still, you don't have to go round and round the asteroid to wrap it up. You can do it using the same principle used in throwing nets: weights along the extremities of your wrapper can be used as projectiles, fired in such a way that when the central part hits the asteroid it'll wrap on its own momentum.

If I understood this correctly, a distant explosion would simply hit the asteroid with a huge amount of radiation, probably causing the vaporization of a relatively thin coat of surface material and maybe pushing it a little bit in the opposite direction. A very little bit. There wouldn't be the shockwave there is on Earth due to the lack of atmosphere, so the devastation associated to it wouldn't happen. I don't think one such explosion can disrupt an asteroid, even if it is just a rubble pile like Itokawa… unless it's a potent blast and/or a close one. The closer you get your explosion, the larger its effects, I believe. In any case, unless your asteroid is pretty small, the kick would be quite small.

A superficial blast would vaporise a considerable amount of material, possibly giving a strong push to small asteroids, but having little effect in larger ones' orbits. But it would also cause a serious seismic activity and the probability of disruption would get much higher.

We don't want that. We want the energy we apply being used to change the asteroid's orbit, not to break it apart, because having several big asteroidal chunks coming our way is hardly any better than having just one. We've seen what can happen when you have a broken small body hit a planet when Shoemaker-Levy 9 slammed into Jupiter. Not a nice sight.

If I understood this correctly. I'm not sure I did. I think I have the right general idea, but some of the details may be off.

Sails are a great idea, but remember you are in space. Sails will do a better job of putting the asteroid into a rotation along the angular axis. Think of a really large sail on a boat without a keel. It will flip right over. In space, you are lacking the keel… so you need a solution for it as well. Adding another opposite of the first doesn't work as well as you might think either… but along those lines is something which could work.

The idea of wrapping the asteroid in reflective material isn't bad; if there is time for it to work, it's simplicity really scores big points from the engineering crowd.

With blowing an asteroid up you would have to get the pieces away from each other so they dont constitute the same big one that wouldnt disintergreat on contacting our atmosphere.

"Why are you guys talking about this stuff?"

Well, the question was asked so why not try to answer it? Perhaps this is not the kind of knowledge our civilization really needs most of all for the moment but it is a nice little trivial exercise.

Oops! I didn't realize that point was a decimal point and I didn't check that piece of the Apophis data myself. Anyway it sound's like a lot less volume than I would expect. Thanks.

/Adam

A question: what would be the difference to a nuke detonated a distance from an asteriod, so the explosion wouldn't damage the asteriod much-to detonating one on the surface of said asteriod?

Fly a spacecraft (Orion?) to the asteroid, plant laser mirrors, seismomitors and take samples from the body.

If Apophis does hit the resonance keyhole, just put a small engine or solar sail on it and you would never have to worry about it again.

It would be a great dress rehersal for a really big threat.

Because as well all know…

Duct tape solves every problem, big or small!

The only technology we have right now, and will have in the near future, would be fusion bombs.

Not sure why people are trying so hard to figure out something different.

Because nuking an asteroid might not work as intended. With nukes you get very different results with relatively small changes in the initial conditions (like how solid the asteroid is, where your bomb explodes, on impact, above the surface, after penetrating, etc.), and you may even cause more havoc than you would if you just let the asteroid hit the planet.

The safest way to deflect asteroids seems to be to push them gently out of the way. Of course, this would only work if you had the time and knew fairly well its orbit with years to spare. Which is why places such as Arecibo are of paramount importance.