NASA slightly raises odds that large asteroid will impact Earth in the next 200 years

NASA this week released updated figures showing a slightly higher impact probability for the asteroid Bennu, a scenario space scientists say is still mostly unlikely. 

The "total impact probability [of the asteroid] through the year 2300 is about 1 in 1,750," NASA said in a press release; that figure is up from an earlier estimate of about one in 2,700. 

Scientists "were also able to identify Sept. 24, 2182, as the most significant single date in terms of a potential impact," the space agency said in the release. 

Researchers are also attempting to determine whether or not Bennu will at some point pass through a "gravitational keyhole," an astronomical phenomenon which can alter the trajectory of asteroids; if Bennu is subject to such forces during a close approach in about a hundred years, it may impact Earth at a future date.