NASA and the National Nuclear Security Administration (NNSA) are researching on how to use nuclear weapons in order to destroy asteroids and meteors that pose a risk to Earth.
Msn.com reports:
Computer simulations suggest that we could successfully blow up a medium-sized space rock.
However, the resulting rock fragments could potentially make the situation worse, depending on how far the asteroid is from Earth when it explodes.
A better solution might be to use the bomb to deflect the asteroid instead of blowing it to smithereens.
Other (non-nuclear) proposals include gravity tractors, using sunlight to “boil off” parts of the Near Earth Object, and using lasers or high-speed spacecraft to nudge the object off of its collision course with Earth. However, a 2007 NASA study indicated that nuclear solutions may be the best weapon we’ve got when it comes to fighting killer space rocks.