Last week the Earth had a narrow escape. The small near-Earth asteroid 2012 DA14 (above) slid by the planet, inside the orbit of the moon and of many satellites. It just shot by us, avoiding potentially cataclysmic damage to whichever unfortunate country (or region) might have happened to be in its way. Had it hit, it wouldn't have meant the end of life on the planet - it was too little for that - but it would have been a hell of a thump. Millions, perhaps tens of millions, might have died.
Still, we got lucky this time. Or did we? It's probably more accurate to say tht being hit by such a small object would ahve been really, really unlucky. Because we're on a tiny rock, in the vastness of space, and DA14 is like a speck on dust on that scale. Bringing the two together? Nearly impossible - and very, very, very (and very) unlikely for all those other dangerous objects out there. Since you're asking, that includes Apophis, once thought of as a danger on a 2036 flyby, and 2011 AG5, which has a tiny (and diminishing) chance of slamming into us in 2040.
But yet there were plenty of us sweating away about dying in a Seeking A Friend For the End of the World-style fireball.
We're pretty bad in general at judging risk. This blogger has never been thought of as a lowly-strung kind of individual, and threw himself to the ground in despair recently at being bitten by a dog in a park. 'Oh no, it's Rabies' - that was the first thought that attacked my fevered brain. Never mind that this happened in Devonport, a suburb of New Zealand's capital, Auckland - a lovely spot, to be sure. And New Zealand? Not only is it officially rabies-free, it doesn't even face you with the risk of bats spreading it, almost uniquely in the whole world. There has never, ever been a single case of rabies there. Ever. Even though it's a dog attack hotspot, with nearly 12,000 unfortunates attacked by canines every year - in a very small country. So, the risks of getting rabies there then? What do you reckon? You've got it: zero, or as close to zero as makes no difference. Yes, you're right. But it made no difference to the fear and anxiety. For a few hours, anyway.
It's a bit like flying. We got the news last week that it's now safer than ever before to fly on a scheduled civilian airliner. It's now been four years since the last fatality on a scheduled civilian flight in the US. But still we're terrified of the things: about 40 per cent of us experience really serious fear of flying.
Why are we so bad at being rational? Well, it's partly that the risk of something happening in these cases may be low, but the consequences if things do go wrong are very, very bad. But it's partly the sensationalist version of what we know, and our inability to fix onto plainer, clearer, more humdrum facts. You're basically going to die of a stroke or cancer, if you're reading this in the developed world. But still your fear of accidents or unlikely contagious diseases blights your life, doesn't it? Have a look at what Daniel Kahneman says about this in his recent best-seller about human psychology, Thinking, Fast and Slow:
Estimates of cause of death are warped by media covetrage. The coverage is itself biased toward novelty and poignancy. The media do not just shape what the public is interested in, but also are shaped by it. Editors cannot ignore the public's demands that certain topics and viewpoints receive extensive coverage. Unusual events (such as botulism) attract disproportionate atttention and are consequenctly perceived as less unusual than they are. The world in our heads is not a precise replica of reality; our expectations about the frequency of events are distorted by the prevalence and emotional intensity of the mesages to which we are exposed.
That's why this sort of tabloid coverage of our near-miss asteroid experience is so unhelpful.
It's what Kahneman means when he talks about an 'availability bias'. What you're told about risk is pretty far from the truth. You've got more chance boring yourself to death in a nursing home than dying in a fireball as an asteroid hits the planet: that's many millions of times likelier, in fact. Do you really think, in your heart of hearts, that you'll experience a similar 'risk event' to winning the lottery and the pools in a single week? Thought not.
I think I'd add 'buoyancy' to this mix - another well-attested psychological attribute that makes us pretty self-centred, but helps us get through the day. We think we're the centre of the universe - we're the centre of our universe, of course - and it makes us resilient. Although that means we usually think we're more invulnerable than others to really nasty stuff, it also means that, in the dark recesses of our minds, that something really dramatically terrible might just hit us. It's the flip side of our human courage and dauntlessness.
But don't worry. Your demise will be pretty tedious, rather than really dramatic. I hope that's of some help to you.