I think about 95% of preparing for Tunguska-type events is to be able to see it coming before it hits, so you can get out of the way or hunker down. I'm not su

I think about 95% of preparing for Tunguska-type events is to be able to see it coming before it hits, so you can get out of the way or hunker down. I'm not sure where we are on that front in general, but the collapse of Arecibo means we've lost our most powerful terrestrial asteroid-tracking radar system. http://www.naic.edu/ao/scientist-user-portal/planetary-sciences http://www.naic.edu/ao/scientist-user-portal/planetary-scien... It's also worth noting that there's a reasonably good chance that we might prevent one or more future Tunguska events by spotting asteroids not right before the collide, but much earlier when they're on a trajectory that will eventually collide with Earth years or centuries in the future.