just last spring, a massive star exploded in a galaxy 3.7 billion years away, collapsed in to a black hole, and produced the biggest cosmic explosion ever witnessed. this was briefly visible in the constellation of leo.
this event created an enormous gamma wave burst, which whizzed harmlessly past earth.
if we had indeed been in its path, our atmosphere would have been blown off and the planet would have been turned in to a cinder. no technology or force on earth could have saved us, even if we had had advanced notice.