It think the idea might be early detection way out and send up something to alter its ever so slightly so that near misses. It would be tough to nuke a big one.
I can’t find the discussions I’ve had on this topic (elsewhere).
The quick and dirty answer is “no”.
What is important in that regards is the amount of energy required to “do something”. Of course you have to decide what it is you want to do.
Do you want to disintegrate the rock, or try to redirect it? Disintegrating takes incredible amounts of energy (think more than the combined nuclear arsenal of all countries). Also, unless you do it early so you can disperse the “clowd”, you still have the same amount of matter hitting the atmosphere at the same velocities, so you still have to absorb the same amount of energy. More will burn up in friction in the atmosphere, but that won’t necessarily be a good thing.
Redirection requires time for the force to work, and a plan on how to make the blast make a nudge work. Given much time and much money we could probably find a way to nudge a rock’s path. But those are strong caveats.
At the moment, we lack the capability to identify and/or track asteroids or comets in Earth-crossing orbits effectively. Not for lack of trying, mind you - there are efforts afoot to chart local space in greater detail (see e.g. NASA’s website on the Spaceguard Survey), but the program is poorly funded at present.
At our present level of detection/tracking capability, it’s doubtful that we’d even see an incoming object more than a few days before it hit, if we saw it at all. Assuming that we could see it… Apart from the technical difficulties Irishman raises, blowing it up might just mean that many areas experience smaller strikes rather than just one big one - not necessarily an improvement. Deflecting an object with our current tecnology requires decades of advance warning, which we don’t have.
BTW, if you decide to check out the movies - “Armageddon” is a fun, action-filled, mindless flick, but loaded with scientific inaccuracies (starting with the opening sequence, in fact). “Deep Impact” does a better job of sticking to science, although it too takes some poetic license.
If it’s an object the “size of Texas”, we’d probably see it from a good distance - if someone looked in that direction. An object that size is larger than the largest known asteroids in the SS.
Well just because theres no air doesn’t mean the bomb throws off any less energy, it just kicks up less dust. I have a hard time believing that a 100megaton warhead couldn’t put a serious dent in a mile wide astroid. And I seriously doubt that we dont have the technology to nuke the astroids, hell the russians were ready to nuke the moon back in the mid sixties. I guess the consenus is that if we blasted it into chunks it would create a global firestorm by peppering the whole earth with little impacts. To really do the job right we would have to have an elaborat method of guiding it away from the earth without pulvarizing it.
BTW it takes a lot of naivete, or a lot of willpower to suspend disbelief long enough to enjoy the movie Armageddon. I certainly couldn’t pull it off.
Well, 100MT would be nifty, if we could do it. The largest thing the US has popped was the 1954 Bravo explosion, at 15 megatons. Part of the problem, as mentioned in previous posts, is placement and timing using the hypothetical 100MT beast.
The easy, dead-on hit would be useless even with a monster nuke. Lots of chunks with the same total energy - shotgun versus rifle.
The nearly impossible nudge from the side, especially if it’s an icy cometary body which will vaporize with some jetting action, could steer the thing away completely if (IF!) you catch it early enough with a hefty warhead.
Early, accurate and powerful, that’s the key. Too bad the funding for Spaceguard is so pitiful, the launch vehicle and delivery requirements so far beyond anything in existence, and the age of the monster nuke so much over.
Given that there’s little to be done about preventing the collision, sling some royalties towards Niven and Pournelle by purchasing “Lucifer’s Hammer,” for hot tips on surviving after we get smacked by a comet.
Sure, I’m all for moderation – as long as it’s not excessive.