Here's What Would Happen if a Huge Asteroid Hit Your City

Would you dissolve in fire or would your clothes simply ignite?

Around the time people in California are getting lunch today, a honking great clod of space rock will be zooming over earth at a hair-raising proximity. (Not this one, as cool as it was.)

Asteroid 2012 DA14 will soar above the planet at a height of about 17,200 miles, above the heads of astronauts on the International Space Station but below the orbits of our geosynchronous weather satellites. The interplanetary cannonball will be so in our face that it might tremble with "asteroid-quakes" caused by the tug of earth's gravity; it's set to become the closest asteroid flyby that we know of since the 1990s.

Sadly for science, 2012 DA14 will not hit the earth and provide a wealth of empirical data on asteroid impacts. But we can still see what the ground-shaking outcome of such a pounding jounce would look like, thanks to this macabre yet fascinating simulator from the excellently named site Killer Asteroids.

The tool estimates the blast radius of several sizes of asteroids using data from Google and this impact calculator from London's Imperial College and Purdue University. To get it working you'll need a GoogleEarth plugin and (at least for me) something other than Firefox. Now, are you ready to virtually decimate some cities? Great, let's go!

We'll begin with Houston, simply because friends tell me it's a rather dull place to live. This is the estimated discus of damage from a "small" asteroid the size of a school bus. A hit from 2012 DA14 would be much more punishing, as it's about 165 feet wide:

Obliteration! Assume everyone in the orange zone is killed instantly. People in the outer yellow area will experience a minor inconvenience as their office buildings fall over like colossal dominoes. Crank up the asteroid size to "medium," with a diameter three times the length of a football field, and you get this blue ring of horrible first-degree burns:

Just for giggles, here's a small asteroid landing a direct hit on Trump Tower:

A medium-sized space rock would wipe out New York City and give Long Island and Jersey residents something more natural (and painful) than a spray-tan:

Hollywood has long obsessed over asteroid impacts – witness Armageddon, Deep Impact, a bunch of crappy made-for-TV flicks, etc. Here's your grim wish fulfilled, Hollywood execs: an asteroid measuring 1.2 miles across (that would be a "large") drilling Los Angeles. If you live in Bakersfield, you'll know the disaster has occurred because your clothes will suddenly be on fire: 

One for our bruthas across the Atlantic:

The simulator lets you toggle between asteroid and comet impacts. How about we destroy Denver with Halley's Comet – look how much harsher the destruction would be, thanks to the comet's bigger size:

(H/t to Google Maps Mania.)

About the Author

  • John Metcalfe is CityLab’s Bay Area bureau chief, based in Oakland. His coverage focuses on climate change and the science of cities.