The old joke about the dinosaurs going extinct because they didn't have a space program may be overselling the need for one. It turns out you can probably divert some of the more threatening asteroids with nothing more than the products of a nuclear weapons program. But it doesn't work the way you probably think it does.

Exploding a nuclear bomb above a huge asteroid could vaporize its surface using X-rays, pushing the space rock away from Earth.

Scientists in New Mexico conducted several experiments and learned that asteroids can be deflected from Earth using explosions of nuclear warheads above the space rock's surface.

Scientists have found nuclear weapons could actually help deflect an incoming cosmic impact — not by blowing an asteroid up, but by showering it with X-ray radiation.