Nuking Asteroids

Experts in planetary defense say we need years if not decades of lead time to successfully deal with an asteroid on a collision course with Earth.  Only weeks advance warning, they say, and we are doomed.

A new study, however, presents an option for that situation-- a nuclear option.  It proposes sending a spacecraft containing two impactors to the asteroid.  The first impactor would drive into the asteroid, creating a deep hole.  It would be non-nuclear.  The second, nuclear-tipped impactor would follow the first into the hole and detonate inside the asteroiid, blowing it apart and sending most of its mass on new paths away from Earth.

It's an innteresting idea, and gives humanity one last shot in a desperate situation.  Hopefully, though, we'll never have to try to make it work for real.