Very Narrow Escape for Ireland

Last night (Thurs 4th Feb 2010) across Ireland sightings of a meteorite were reported. At 6PM people from across the country saw the blazing chunk of space-rock travelling at around 100,000 miles per hour streak across the sky before lighting up like a small nuke and vanishing.

Ireland was lucky - this is exactly the same sort of event thought to have caused the Tunguska incident. The distance such a meteorite penetrates into the atmosphere depends more on its physical make-up than its size. If it is oddly shaped it heats up quickly and if it has internal faults can shatter and explode with great force equivalent to a tactical military Nuke (say 1 Kiloton).

According to David Moore of Astronomy Ireland .. 'This is a huge event.'

Well it could have been more huge. Apparently witnesses who saw it were facing inland at the time which indicates that any fragments of rock landed on ground and not at sea. This could spark a mini Irish Gold Rush since the last such meteorite fetched around $500 per gram - better than its weight in gold!

This is what is known as putting a positive spin on things since to penetrate at all the meteorite must have been rocky and a rocky meteorite even a 'small' one can do a lot of damage if it does not explode high up.

Space Rocks of up to 500 meters in diameter are quite common - luckily it is doubtful if the Irish meteor was bigger than a football. A fifty meter sized asteroid would have produced a 1000 meter crater in the old country and unleashed a shock wave big enough to destroy a small town.

Statistical research by Professor Mark Bailey shows that an object large enough to cause a 10km crater (a 6-700 meter chunk of rock) hits the earth on average every 80,000 years. This would be like pushing the 'reset' button on civilisation - such an impact has global effects being able to cause ice-ages and Tsunamis big enough to scour whole countries. Thats without the increased vulcanism.

There are 1500 objects of size 1km and over that we know about which regularly cross earths orbit - and god knows how many more that we have no clue about because their orbits are odd, or long-period.

Time to buy an umbrella...