[hoorayimhelping]

Capable with current technology if intercepted early enough. I think most people visualize an asteroid hitting earth like a ball hitting the ground when dropped at arm's length. In reality, orbits of celestial objects are elliptical, and they're constantly moving. A small force, like that produced by an ion thruster, applied to an asteroid 15km in diameter for months or years would be enough to change it's orbit such that it wouldn't impact earth.