x Abu Dhabi, UAETuesday 20 February 2018

When it comes to dangerous asteroids, any solution is still a fantasy

Thousands of asteroids are heading our way, some with the potential to explode in our atmosphere with the force of a nuclear arsenal. The good news is that we are getting pretty good at spotting them. But what then?

Illustration by Sarah Lazarovic for The National
Illustration by Sarah Lazarovic for The National

Back in September, The Takeawaywas gazing up at the sky in trepidation at the news that yet another piece of redundant manmade space junk was hurtling back to Earth, threatening to extensively remodel someone's lawn.

Four months later and we are ducking again, but this time the author of our fear is not some rocket scientist who forgot that what goes up must come down, but the universe itself.

It isn't, it turns out, the old tin cans we should be concerned about so much as the thousands of Near-Earth Objects (NEO) - asteroids large and small - heading our way, some with the potential to explode in our atmosphere with the force of a nuclear arsenal and cause an Extinction Level Event.

Remember the dinosaurs? Well exactly.

The good news is that we are getting quite good at spotting these things. So far Nasa, which began looking in earnest in 2005, has discovered 8,000, with another 70 popping up every month.

The bad news is that we aren't yet good enough at spotting them and, even if we did spot one about to bash into is, there isn't much we could do about it.

Take the asteroid 2012 BX34, an 11-metre rock that whipped past the planet at about 8pm UAE time last Friday: 60,000 kilometres might not sound like a near-miss, but that's just one sixth of the distance to the Moon and, travelling at close to 50,000kph, BX34 was just a little over an hour away from dropping in.

And, in a nutshell, we didn't see it coming - the first anyone knew about it was the previous Wednesday. And BX34's near-miss barely made it into the top-20 of such near misses.

"There is," Gareth Williams of the Minor Planet Centre told the BBC, after some no-doubt fevered calculations, "absolutely no chance of it hitting us" - which was just as well, as a paper published last week, with impeccable timing, made clear.

"There is currently no concerted international plan addressing the impact threat and how to organise, prepare and implement mitigation measures," was the headline point from the paper, A Global Approach to Near-Earth Object Impact Threat Mitigation, written by a collaborating group of scientists from the US, UK, Russia, Germany, France and Spain.

There is no shortage of ideas, say the scientists - just a shortage of political will and cash to get them off the drawing board: in theory, "kinetic impactor" spacecraft could be launched, a so-far entirely imaginary "Gravity tractor" could be deployed on sentry duty or (and this, you will remember, was Bruce Willis's favourite option, as modelled in the 1998 film Armageddon), we could nuke 'em.

But whatever solution we choose, we should choose it soon. Looming just over the horizon is the potentially apocalyptic asteroid Apophis - and the clue is in the name. Apophis was an ancient Egyptian demon, aka The Uncreator.

This 330m-wide rock is due to come awfully close in 2029 - just 29,470 km close, says Nasa - but it will miss us. Phew.

When it returns in 2036, however, there could be "a small estimated chance of impact" (though "less than 1 in 45,000" doesn't sound that small) while new measurements possible in 2013 would "likely confirm" that Apophis will miss us by millions of kilometres.

Likely? Sort of reassuring. Except Russian scientists don't agree.

What's "likely" for them, said Professor Leonid Sokolov of the St Petersburg State University, is that a "collision with Earth may occur on April 13, 2036".

Nasa remains sanguine. "The threat to any one person from auto accidents, disease, other natural disasters and a variety of other problems is much higher than the threat from NEOs," it says.

"Our best insurance rests with the NEO scientists and their efforts to first find these objects and then track their motions into the future."

Fine. But then what? Send for Bruce?