Right now we don't know of any asteroids ... are that are going to hit the Earth for the next hundred years, says Terik Daly...
Astronomers estimate that there are roughly 25,000 of these near-Earth objects that are 140 meters across or larger, but only about 43% have been found to date...
This event was just the latest in a series of drills that planetary defense experts have held every couple of years to practice how they'd handle news of a potentially planet-menacing asteroid...
Even an asteroid on the smaller end of that range could have a big impact, depending on where it hit the Earth, says Lindley Johnson, NASA's Planetary Defense Officer Emeritus...
[
Collection
]
[
|
...
]