There are more than 1,400 potentially dangerous asteroids orbiting alongside the
Fortunately,
To make this list an
The Near-Earth Object Project Office at Caltech's Jet Propulsion Laboratory has been monitoring them since 1998, and publishes information about these and other asteroids and their "impact risk."
It may sound like they are on top of this Earth-ending asteroid thing, but really, not so much. NASA notes that there is no "government agency, national or international" tasked with stepping in should an asteroid decide that Earth is in its way.
That's probably because we haven't found one that's going to end us yet. "None of these PHAs is a worrisome threat over the next hundred years," NASA said.
We know that apocalyptic asteroids have hit in the past — paleontologists believe an asteroid that struck Mexico's Yucatan Peninsula was at least in part responsible for the mass extinction during the late Cretaceous that killed off 50% of the world's species, dinosaurs among them.
An asteroid about the size of a basketball hits and burns up in Earth's atmosphere about once a day. Larger ones about the size of a car do the same a few times a year, disintegrating into stunning fireballs.
We saw recently how frighting and destructive these near-earth objects can be when a meteor exploded over the Chelyabinsk region of Russia on February 15. An Earth-ending Asteroid would be much, much worse.
But such events only occur once every several million years, and a meteorite the size of Chicxulub, the one that hit the Yucatan in the late Cretaceous, occur only once every 100 million years.
But, eventually, one will strike. Scientists are already aware of the asteroid RQ36, which has a 1/1000 chance of destroying life on Earth in 2182.