Posted by Laura

What were you doing on March 23, 1989?

Not sure? Come on, you can do better than that. Nope? Then let me jog your memory a little: it was a momentous day – one that sent intergalactic shockwaves pulsing through the universe, changed the face of mankind as we knew it, and transformed the atmosphere on earth so radically it became just another isolated orb within the vast, star-strewn blanket of the Milky Way. Well, Nearly.

But this was a significant “nearly”. This time 18 years ago, our planet was skirted by an asteroid the size of a mountain which, had it struck, would have left a crater the size of Washington DC and caused unimaginable environmental and climatic devastation that no Hollywood fantasist could conjure up. How near were we to this Armageddon? About 500,000 miles or so - but still a very close call in scientific terms. So close, that March 23 will be forever remembered as Near Miss Day.

There have been other near misses since then. In December 1994 a small asteroid passed within 65,000 km of the planet. In June 2002, an asteroid, big enough to devastate 2,000 sq km but small enough to escape detection, skimmed Earth by a whiskerish 120,000 km. Luckily for us it missed – scientists didn’t actually see it until three days after it hurtled past at 10.6 km per second.

Close encounters of the cosmic kind are not as infrequent as you might think. The NASA website’s Near Earth Objects section reveals upcoming “close approaches” virtually every other day. Fittingly, there are two such passing visitors on March 23 this year  -  objects  2006 JY26 and 2007 FJ1 – but at 13,440,000 km and 14,284,800 km away respectively, their presence is not of the nature to make the space bods even break a sweat.

The really close ones, like those mentioned earlier, are of more interest. Astronomers estimate there are several each year, many only getting detected as they reach their closest point to earth, or after they have passed. Experts suggest there could be up to a million smaller, hard-to-detect asteroids with the potential to cause local devastation. But, before we brace ourselves for the world to be saved by Bruce Willis armed with some specially-adapted drill, the odds of us coming into contact with such matter are minuscule.

The bigger objects, with which a collision could pose significant global devastation, are closely monitored by specialist groups. But again, the possibility of any being on a trajectory to collide with earth is extremely unlikely. And, according to NASA, they would be identified early enough to use technology to deflect them away from our planet. The space agency rightly plays down the risk to earth from asteroids, but the chance of an impact over long periods of time is not entirely negligible.

Perhaps it’s best that on March 23, 1989, most of us marked the historic near miss by being blissfully oblivious to the monster in our midst.  Trying to work out the likelihood of an asteroid collision is enough to send even the most mathematical of minds into orbit. But this doesn’t make the notion of the great intergalactic unknown any less fascinating.  When I was first taught the big bang theory at school I spent many idle minutes letting my train of thought get caught in a perpetual loop of “if”. If the gravitational forces hadn’t been such to create the universe then would there just be a great expanse of nothing, and therefore no one to question how and why it all happened and to wonder, in turn, what would have been if it hadn’t all happened, hence no one to ask the question, “if”? I’m getting dizzy already.

There’s precious little time for infinite thoughts with no boundaries like these in chaotic modern life, so should we really be wasting more minutes marking a day which was generally as unremarkable as any other – only distinguished from the blur of weeks, months and years by something that didn’t happen? There are now so many symbolic days in our calendar it is difficult to keep track. Monday, for instance, is ironically Make Up Your Own Holiday Day. And Wednesday is Something On A Stick Day - thought up, presumably, by a very bored person on the previous year’s Make Up Your Own Holiday Day.

Every day has a significance now, it seems. Many mark grave events, or the resulting joy after the ending of such grave events. We commemorate wars, liberation from oppressive regimes, deaths, disasters. Yet this is precisely why I won’t be letting Near Miss Day pass without a knowing look skywards this year. Yes, it represents an almost, a nearly-but-not-quite. But it also symbolises the unquantifiable, the unknown, the beyond-fathomable enormity of what lies outside the trivialities of the day-to-day world and our view of it. Near misses remind us of just how small we are in the grand scheme of things, of the force of consequence and, ultimately, the power of the universe that surrounds and supersedes us. And that has got to be worth a pause for thought.

What do you think? Should we mark Near Miss Day? Let us know your thoughts and experiences.