We basically have no defences against a surprise comet or asteroid

Alan Martin December 19, 2016

Given the terrible state that 2016 has left the planet in, you’d imagine things couldn’t get much worse. But should the year have one final surprise twist in the tail and throw us news of an incoming asteroid or comet on a collision course with Earth, there’d be worryingly little we could do about it, according to NASA scientist Dr Joseph Nuth.

We basically have no defences against a surprise comet or asteroid

“The biggest problem, basically, is there’s not a hell of a lot we can do about it at the moment,” explained Nuth from NASA’s Goddard Space Flight Center at the American Geophysical Union’s general meeting last week.

The good news is that the kind of asteroid or comet we’d need to be afraid of is astonishingly rare. The vast majority of small objects that hit us break up in orbit. “But on the other hand there are the extinction-level events, things like dinosaur killers, they’re 50 to 60 million years apart, essentially. You could say, of course, we’re due, but it’s a random course at that point.” earth_powerless_against_asteroid_event_right_now

Random or not, there have been a couple of close encounters during our lifetimes – most recently in 2014 when a comet passed “within cosmic spitting distance of Mars”. The worrying this about that is that although we had some advanced warning – 22 months to be precise – that’s nowhere near enough time to initiate a defence strategy should a similar object line up with Earth tomorrow. “If you look at the schedule for high-reliability spacecraft and launching them, it takes five years to launch a spacecraft. We had 22 months of total warning.”

Nuth’s recommendation to counter this problem is for NASA to build an interceptor rocket that would be kept in storage until needed. With regular testing, a rocket could be ready to launch relatively quickly to “mitigate the possibility of a sneaky asteroid coming in from a place that’s hard to observe, like from the sun”.

Right now there is no plan in place to act on this – such a plan would need to come from NASA’s administrators and be approved by congress. For the time being, we just have to cross our fingers and hope that our 65-million-year lucky streak continues for a little longer.