CC,
Just a couple of other interesting facts concerning comparative impact/detonation yields of nuclear weapons vs. meteor impacts.
(some images are disturbing)
http://www.csi.ad.jp/ABOMB/record.html
The bomb
little boy was dropped on Hiroshima. It had a comparitive yield of only 13-16kt.
Fat Man was slightly larger at about 21kt. These comparatively small explosions caused enormous ammounts of devistation for such small yield warheads.
The current US aresonal of thermonuclear devices have the following yields:
Little Boy.........13-16kt (Hiroshima)
Fat Man............21k (Nagasaki)
The W-76.........100 kiloton
The B-61.........350 kiloton
The W-87.........300 kiloton
The W-88.........475 kiloton
Ivy King...........500 kiloton
Orange Herald.700 kiloton
The B-83.........1.2 megaton (the most power currently active)
The B-53.........9 megaton
Castle Bravo....15 megaton (the most powerful tested by the US)
Tsar Bomba.....50 megaton (the most powerful ever tested USSR)
Impactor size for cratering though depends on size/density of the impactor and angle of impact. a more direct blow requires a smaller impactor and yields less energy.
To create a crater that is 1k dia.
for an Iron impactor,
90deg impact it needs to be 190m dia and hits with the force of 991 kiloton
for a dense rock impactor
90deg impact it needs to be 289m dia and hits with the force of 1.31 megaton
for a porous rock impactor
90deg impact it needs to be 388m dia and hits with the force of 1.59 megaton
At the other end of the spectrum
Iron
10deg impact needs to be 401m dia and hits with the force of 9.35 megaton
dense rock
10deg impact needs to be 610m dia and hits with the force of 12.3 megaton
Porous rock
10deg impact needs to be 821m dia and hits with the force of 15 megaton
So, if Barringer crater was made by a porous rock meteorite that was 820 meters diameter and struck at a 10deg angle, it would have the explosive force of our most powerful thermonuclear device ever tested (in the US), 15 megatons. I doubt anything would be left of the impactor.
If the impactor were dense rock that was 307 meters diameter and came in at a 60 deg angle, it would have the explosive force of a 1.57 megaton device, still more energy than our most powerful thermonuclear device in active service. I still doubt anything would remain of the impactor.
In short, the biggest Nuke we have is insufficient to create one of the smallest craters on earth. Nukes aren't the answer, Impactors carry the sufficient force needed, not only to excavate the crater but also to destroy its cause.