NASA to Chase Asteroid That Has Slight Chance of Hitting Earth

There's an asteroid out there that might slam into Earth in about 170 years, but contrary to some recent scary-sounding headlines, it won't wipe out Earthlings if it does, reports Space.com. "We're not talking about an asteroid that could destroy the Earth," says Dante Lauretta of the Lunar and Planetary Laboratory at the University of Arizona. "We're not anywhere near that kind of energy for an impact." In fact, the odds that asteroid Bennu will strike Earth are just 0.037%, a 1-in-2,700 chance, according to NASA calculations, which are expected to become more precise thanks to a new mission. OSIRIS-RE will lift off on Sept. 8 and spend two years hunting the asteroid, then study it for another couple years before bringing at least 2.1 ounces of its surface back to Earth in 2023.

Questions will focus on, say, whether asteroids delivered organic matter to our planet, but the mission will also "allow us to recalculate the impact probability," Lauretta adds. The asteroid crosses our orbit every six years. If it hits a so-called "keyhole" when it passes by Earth in 2035, it would be put on track to collide with the Earth in 2185. Astronomers estimate that space debris has to be at least 0.6 miles wide to be seriously catastrophic; as a frame of reference, the asteroid believed to exterminate the dinosaurs was closer to 6 miles across. Bennu, which was first spotted in 1999 and is classified as a potentially hazardous asteroid, measures about 1,600 feet across, notes Time. (That asteroid that claimed dinos almost wiped out all mammals, too.)