Asteroids hit the Earth every day. Most of these rocks and chunks of ice are dust-sized and are harmless to our planet. But some are more threatening — like the asteroid that wiped out the dinosaurs.
At least 10,000 dangerous objects are closing in on Earth, said U.S. space agency NASA in June. Just one year ago, a 20-meter-wide asteroid exploded over Russia. It generated the force of a medium-sized atomic bomb. People on the ground were burned by its extreme brightness — 30 times that of the sun — and at least 1,210 were wounded by falling building debris or flying shards of glass.
The positive side? Asteroid collisions can often be anticipated, and unlike volcanic eruptions, tsunamis and other natural disasters, they may even be prevented. Enter the Asteroid Terrestrial-impact Last Alert System (ATLAS), geared for full operation in 2016.
ATLAS, developed by the University of Hawaii and funded by NASA, consists of two telescopes 160 kilometers apart. They can detect objects 100 million times fainter than a bright star in the sky. All night long they ignore the stars and snap photos of asteroids. Astronomers all over the world can then determine their trajectory within a few hours.
“Our target asteroid is one on a ‘death plunge’ trajectory,” said Larry Denneau, an engineer who oversees the telescopes’ software. That could mean a 100-megaton asteroid capable of wiping out an entire county. People at its point of impact would receive up to three weeks’ notice, allowing them time to evacuate.
Some day, advance notice could even assist scientists in diverting asteroids before they strike Earth. Techniques being explored include knocking asteroids in other directions, like a celestial pinball machine, or using the gravitational pull of spacecraft to tug asteroids into other orbits.
“At what point does this go from being a science problem to a national security problem?” said Denneau. It’s all starting to sound a lot like science fiction — but addressing both challenges has never been more possible.
Interested in asteroids and all stuff that is space? Explore the work of NEOShield, a collaboration between the United States, Russia and several European Union countries to deflect hazardous objects. Help keep tabs on asteroids close to Earth with NASA’s free app, the Asteroid Watch Widget. To get the latest news and photos on asteroid activity, connect to NASA’s Asteroid Watch.