NASA asteroid warning: 700 foot space rock on risk trajectory with Earth in 2023
express.co.uk
express.co.uk
(4/3) * pi * (213/2 [m])^3 * 3 [g/cm^3]
Mean diameter: 213m
Kinetic energy is 0.5 * m * v^2, so figure 10 [km/s] which works out to 7.59e17 [J] or 181 MT of KE total. The airburst is around the square root of that, so 13.5 MT.
If it hit just right, it would be big enough to wipe out a large city metropolitan area. The odds of it hitting at all aren't that great.
Postscript: There ought to be a scifi weapon that flings pyramids.
Theres a recurring trope of advanced civilizations (human or alien) using directed asteroids as weapons. In this case Starship Troopers is the first example that comes to mind.
I'd never seen it coherently, all the way through. I really enjoyed watching it again, and fully.