Odds on Asteroid Hit Going Up

The good news is that scientists have a better handle on asteroid Bennu's whereabouts for the next 200 years. The bad news is that the space rock considered one of the two most hazardous known asteroids in our solar system has a slightly greater chance of clobbering Earth than previously thought. But don't be alarmed: Scientists reported Wednesday that the odds are still quite low that Bennu will hit us in the next century, per the AP. "We shouldn't be worried about it too much," said Davide Farnocchia, a scientist with NASA's Center for Near Earth Object Studies, who is lead author of the study published in the journal Icarus. While the odds of a strike have gone from 1-in-2,700 to 1-in-1,750 over the next century or two, scientists now have a much better idea of Bennu's path thanks to NASA's Osiris-Rex spacecraft, Farnocchia said. "So I think that overall, the situation has improved."

The spacecraft—returning to Earth with samples from Bennu, to arrive in 2023—collected enough data over 2.5 years to help scientists better predict the asteroid's orbital path well into the future. Bennu will have a close encounter with Earth in 2135 when it passes within half the distance of the moon. Earth's gravity could tweak its future path and put it on a collision course with Earth in the 2200s—less likely now based on Osiris-Rex observations. If Bennu, about one-third of a mile in diameter, did slam into Earth, it wouldn't wipe out life, but rather create a crater roughly 10 to 20 times the size of the asteroid, said Lindley Johnson, NASA's planetary defense officer. The area of devastation would be as much as 100 times the size of the crater. An impact on the Eastern Seaboard "would pretty much devastate things up and down the coast," he told reporters. But "100 years from now, who knows what the technology is going to be?" (NASA could blow it up.)