NASA scientist: Earth is overdue a dinosaur-killing asteroid strike, and we're woefully unprepared
At the annual meeting of American Geophysical Union last week, the Guardian reports that Dr Joseph Nuth, a researcher with NASA's Goddard Space Flight Center, said that Earth is woefully unprepared for an asteroid strike. We're particularly defenceless if it's the size of the one that is thought to have wiped out the dinosaurs.
Although rare, Nuth said of dangerous asteroids and other space rocks: "They're 50 to 60 million years apart, essentially.
"You could say, of course, we're due."
It is generally believed that dinosaurs became extinct around 66 million years ago after a 10km-wide asteroid hit the area which is now the Gulf of Mexico.
Nuth said that Earth had a "close encounter" with a comet in 1996 and again in 2014, when one passed "within cosmic spitting distance of Mars." In that case, if we had been unlucky and the asteroid was in fact heading towards us, we probably wouldn't have had enough time to prepare.
We have the technology to deflect asteroids of basically any size.
Taking on an asteroid would probably require two space missions, said Nuth.
The first mission would send a robotic probe towards the asteroid to knock it off course. The second mission would be a follow-up to launch a "gravity tractor" spacecraft to fly alongside the asteroid to nudge it further and further away by using a gravitational tug.
Such a strategy would probably only work on asteroids up to 400m wide. Larger space rocks would require several impacts from probes, or attempts to destroy the asteroid with a nuclear bomb.