Front page of the Wall St Journal has a big drawing of asteroid 2005 YU55, which crosses earth's orbit and came within 201,000 miles of earth (inside the Moon's orbit) Pretty science fictiony for the staid old Wall St Journal.
This one missed.
Question: what should we do when we detect one that's gonna hit us? The only thing that might do some good, it to nuke it. Good big nuke, close up, might blow it into gravel. Or it might break it up into a dozen pieces. But the pieces keep coming. What causes more damage, one really big hit, or a dozen smaller hits?
Do any of those ICBM's have the oomph to boost a big nuke up that high? These asteroids are small and dark and hard to see, so they will be real close before we spot them. No time to build a special rocket, we would have to use something off the shelf. That's an ICBM that's been standing silo alert for decades. Or possibly a satellite launcher from Space-X.
If we have enough delta-V to do a rendezvous and land on the thing (heh, works in the movies) we could set a big nuke on one side of it it. Set it off, and that rock is gonna move. Trouble is, it may not move all that fast, which means we gotta nuke it when it's far out there, to give it time to move far enough to miss the earth.
Do we have any rockets with that sort of delta-V?