Scientists who study asteroids often say that Earth is drifting through a cosmic shooting gallery.
Some space rocks are so large that they can shatter walls and break windows. Others, like the one that caused the Tunguska Event of 1908, can flatten entire cities. A handful can trigger global extinctions, like the asteroid that smashed into Mexico’s Yucatan Peninsula 66 million years ago.
But how big of an asteroid does it take to damage cities, states, countries, and the planet?
We take a look at estimates from NASA, Purdue University’s “Impact Earth” simulator, and other sources.
Images in this story come from a previously published video.
Most of us go through life without thinking much about rocks from space. But even a small — and relatively frequent — asteroid can inflict great damage.By numbers, most meteors are smaller than a car and burn up in the atmosphere as harmless meteors.Any larger than that, and things start getting risky.Some detonate into airbursts high above the ground. These explosions create shockwaves strong enough to break windows.They can also emit enough light energy to cause a sunburn.A house-sized meteorite can explode in Earth’s atmosphere with a force greater than the nuclear weapon the US dropped on Hiroshima in 1945.Such a space rock could flatten most buildings within 1. 5 miles of ground zero.
An asteroid the size of a 20-story building is bad news.With the right composition, speed, and angle of attack, a rock this size might leave a wake of destruction the size of central Paris.One roughly the size of a football field could obliterate New York, causing a 7. 7-magnitude earthquake that might be felt than 1,000 miles away.An asteroid more than half a mile wide would start to have global implications.It could destroy an area the size of the US state of Virginia.Dust tossed up from the impact would block the sun and lead to rapid changes in climates across Earth.
A Mount-Everest-size space rock would vaporize everything around its impact site for miles.The resulting crater would stretch more than 100 miles wide.The aftermath that follows would kill most life on Earth.In fact, this is similar in size to the space rock that killed the dinosaurs.A London-sized asteroid would be more than just a major extinction-level event. Its impact would slow down Earth’s rotation enough to make its day last almost half a second longer.
The biggest known asteroid is Ceres. It’s about the same size as Texas. Luckily for us, Ceres will never hit Earth. Watch our video to learn more about what damage an asteroid can cause.
Correction: A previous of this story had an image and caption about a Mount-Everest-size impactor accidentally deleted. This temporarily made the effects a half-mile-wide space rock impact sound (much, much) worse.
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