210811_Bennu_Keyhole.jpg

Illustration of where Bennu would need to pass to be on a trajectory to Earth. NASA/Goddard In 2135, asteroid Bennu will make a close flyby of Earth. Our planet's gravity will tweak Bennu's path, making it a challenge to calculate its future trajectory. During the flyby, Bennu has an extremely small chance of passing through a gravitational keyhole that would set it on a path to impact Earth late in the 22nd century.