The chance of a city-killing asteroid striking Earth is higher than scientists previously believed, a nonprofit group building an asteroid-hunting telescope said Tuesday.
A global network that listens for nuclear weapons detonations detected 26 asteroids that exploded in Earth's atmosphere from 2000 to 2013, data collected by the Comprehensive Nuclear Test Ban Treaty Organization shows.
The explosions include the Feb. 15, 2013, impact over Chelyabinsk, Russia, that left more than 1,000 people injured by flying glass and debris.
"There is a popular misconception that asteroid impacts are extraordinarily rare . . . that's incorrect," said former astronaut Ed Lu, who now heads the California-based B612 Foundation.
The foundation on Tuesday released a video visualization of the asteroid strikes in an attempt to raise public awareness of the threat.
Asteroids as small as about 131 feet (40 meters) — less than half the size of an American football field — have the potential to level a city, Lu told reporters on a conference call.