Wednesday, 4 February 2015

Near Miss

I am always a bit wary about the statements of Experts who, in a single breath, start off with reassurances that something is definitely not a threat but realise that they are setting themselves up for a fall and then say that the chances of the thing occurring are extremely remote and if it did happen the outcome would probably not be catastrophic.

Talk about couching your answers and opinions.

Of course, if the Expert was a weather man we would just expect the complete reverse of the forecast. If a banker or financier we have learnt that such talk would prompt us to go down to the Building Society and draw all of our pennies out and stop off at Tony's Textiles to buy a large pillowcase. If coming from your own Doctor it is probably time to think about putting your affairs in order. The same sequence of words from the mechanic at the High Street garage would invoke serious doubts about ever buying a British made car ever again.

In this particular instance the phrases came from one of the scientists at the asteroid tracking centre at NASA in relation to a lump of space rock, unimaginatively labelled 2012 DA14 which, around the 15th of this month, will set a new record for the largest object to pass closest to the Earth and be known about, ie not sneaking up and giving Bruce Willis and Co only a handful of days to save the Planet.

I have reservations about the familiarity by which DA14, call it DALE for the fun aspect, is known to NASA in that DALE was only recently discovered by a team of amateur astronomers in Spain. I have seen a pictorial representation of the sighting of DALE and believe me, it must have been spotted in the morning before an Iberian liquid lunch because it is but a small, very fast moving speck amongst swirly specks and could as easily have been a black thunder-fly skating across the telescope lens

In the hands of NASA with all their computing power it has been possible to produce a three dimensional model of DALE and it resembles, for easier appreciation, a pumice stone (Boots The Chemist 99p) or small oval shaped sponge (Halfords 99p).

Seemingly innocuous until scaled up to about half the size of an American Football Field.

I was, and still am, an avid follower of space and science fiction themes and I recall reading about the 1908 event in Siberia where something exploded above the frozen, forested wastes at Tunguska and levelled many hundreds of square miles as well as leaving the animal population barbecued and the sparse human population as a statistic as missing or gone on an extended ice fishing trip. The nice man at NASA felt that DALE was roughly about the same size as whatever re-modelled that part of Russia. Oh, and also similar in size to potentially create as much as a tourist attraction as Meteor Crater in Arizona, as soon as the fires, dust and mayhem settle down.

So, how close is close?

It has been necessary for NASA to contact all of the operators of communication and other satellites to alert them to the predicted path that DALE will take because it is to be within their orbital path, around 22,000 miles above Earth. Apparently, our entertainment and viewing schedules will not be interrupted or rather promptly terminated  on the basis of the positive responses from the respective companies.  If you do, however, see one of those Test Cards on your screen in place of your regular programme on Feb 15th do be sure to check that your satellite dish has not been stolen before going down to your asteroid shelter.

For visualisation purposes the passage of DALE will be within the orbit around Earth of the Moon at around 17,200 miles above my house, and yours. It is reassuring, again from the rather vague and typically condescending comments by our Asteroid Expert that something of the size of DALE comes by every forty years or so but the probability of an actual strike is more relaxed at one every 1200 years. He declined to comment when the last strike was.

A comforting thought is that DALE is not made of dense iron like the rock that is thought to have wiped out the dinosaurs but even if made of cheese the potential for damage in a fast moving impact with Earth would be big (I have adopted the NASA 'don't panic the people policy' by using 'big' and not a word to mean anything more destructive).

Those in a position geographically and equipment-wise to witness DALE's near miss will be few because of its sheer velocity and dust speck comparative size in the backdrop of deep space.

I just hope that the middle aged scientist responsible for predicting DALE's journey around Earth's inner-ring road and by-pass is not that clever, bespectacled, geeky lad who sat next to me in Maths at school and always wanted to work for NASA when he was grown up because I remember playing with and breaking his faithful slide rule so that his subsequent answers were always about 17,201 units from the actual.

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