One point three in a billion. Tim De Chant does the math at Per Square Mile:
So you're telling me there's a chance. The leading dinosaur extinction theory has cast a long shadow over our feeble sense of existential security. If it could happen to giant armored reptiles, it could happen to us, too.
But ease your worried minds, meteorophobics of the world. The numbers don't lie. It's not going to happen. But it's not not going to happen, either. I mean, we can't rule it out entirely. What if that "large asteroid" lands in the ocean and whips up a tidal wave that then goes on to destroy the city?
Which is perhaps why both Armaggeddon and Deep Impact were both made into action flicks that one fateful summer back there. Excited media execs probably figured an earthbound asteroid for the perfect blockuster villain: deadly, all-powerful, nonpartisan, and so implausible that moviegoers would be able to forget about the nonexistent threat by the time they filed out of the cineplex's lobby. It's threat ephemeral par excellance.
But it is also probably why there hasn't been another asteroid-from-hell flick since. Too ephemeral. Too dull.
Just not for NASA, which is at least concerned enough about an asteroid colliding with Earth to build an underwater sealab to study how to stop it.
Apologies, I've gone and roused your fears again. If you can't shake it, just heed the sage advice of Fear of Stuff.
How to Overcome Meteorophobia?
Consider for a few minutes the number of people you personally know who have been injured by a meteor or meteorite. Advance that thinking to the number of homes you personally are aware of in your city that have been damaged by a meteor or meteorite. Hopefully the answers help place the fear in perspective.
Of course, that may not be as soothing if you happen to live in Chelyabinsk, Russia, and some 1,000 of your friends and peers are still recuperating from meteor-inflicted wounds. Because while it is extremely unlikely that meteors will destroy your city, it is slightly more likely that they will shatter the glass of its buildings and give you some solid dash cam footage.
There's only a one in a billion chance that it's going to kill you.