This experience shows us why we need to spend mega bucks over the coming decades to track all these space rocks even the smaller ones. Right now when one thinks about it you could have an asteroid that could put us into an Ice Age NASA is watching on a course away from Earth. Then a 120 foot rock at high speed that we didn't notice hits it and all the sudden we have a half mile wide asteroid heading to Earth with little time to respond.
I would also support the creation of a few devices to move such a space rock into a different course. But, if we don't have time we should build the mother of all nukes (something in the multi gigaton range)... perhaps even using anti matter when we are able to do so as a last line defense. We don't want to suddenly go the way of those big lizard like things that kept us mammals hiding in trees and underground.