According to the report, impactors measuring between 1,312ft and 5,249ft (400m and 1,600m) in diameter can destroy an entire continent.
Asteroid PZ39 sits right within that scale, believed to measure between 1,443ft and 3248ft (440m to 990m) across.
For comparison, when a six-mile-wide (10km) rock struck the planet about 66 million years ago, the impact wiped out the dinosaurs and two-thirds of life on Earth.
The White House report said: “Larger NEOs greater than 140m have the potential to inflict severe damage to entire regions or continents.
“Such objects would strike Earth with a minimum energy of over 60 megatons of TNT, which is more than the most powerful nuclear device ever tested.
source: express.co.uk