NASA has rammed an asteroid at blistering speed in a practice run just in case something much larger threatens the Earth.
The odds of such an occurrence are exceedingly low, but we have seen asteroids heading for Earth in a number of movies now. So people are interested, because we imagine the worst.
Naturally since the collision was at very high speed, all transmission stopped at them moment of impact (yes, the radio broke). It will take many months to find out exactly how much the asteroid has been deflected.