08-11-2008 Celtic Rock - Irish Asteroid Discovery (Article

[Simon Kenny]

Celtic Rock - Irish Asteroid Discovery (Article 162)
In 1848, Andrew Graham stared through the telescope at Markree Observatory in County Sligo and saw a new object. He discovered an asteroid we now call Metis - a chunk of rock left over from the formation of our Solar System 5 billion years ago. As it happens, this chunk of rock (about 230 miles in diameter) was the ninth asteroid ever discovered world-wide and the only one discovered from Ireland.

Fast-forward 160 years to October 2008, County Kildare...

One of only 1400 Observatories world-wide, Celbridge Observatory has been diligently logging the positions of asteroids for the last three years and is owned and operated by Dave McDonald, a keen amateur astronomer. The data gathered is submitted to the Minor Planet Center (MPC) which provides accurate orbits for hundreds of thousands of asteroids.

Of special concern to the MPC, and humanity, are those asteroids that pose a risk of colliding with Earth. We know that Earth has been impacted many times in the last few billion years - most are of no consequence but some have been responsible for wide-scale devastation and long-lasting damage. Certainly, modern man has not seen any impacts of such huge proportions - but we need to be vigilant.

This is why Dave and others keep a close eye on the heavens to spot any asteroids with the name "Earth" written on them.

It was during one such survey on Tuesday 7th October 2008 that Dave spotted a very faint moving object - half a million times dimmer than the stars you can see at night. Following discussions with colleagues, he took another look at the object the next night and sure enough, it was still there.

Having ruled out space junk or even a bit of dust in the observatory telescope, Dave submitted the data to the MPC. After a short wait, the MPC replied that it was indeed a new asteroid discovery and gave it a temporary name of 2008TM9.

So, what do we know about the second asteroid ever discovered from Ireland? As luck would have it, it certainly does not have Earth's name on it. 2008TM9 gently orbits our Sun way out beyond Mars and it has no intention of coming any closer to us than about 225 million miles. With a diameter of around a mile, that's good news - it would have the ability to wipe out an entire continent.

In coming years, as the orbit is refined, 2008TM9 will become a 'numbered' asteroid. At this point, Dave will have the opportunity of giving the asteroid a name. So, what’s it going to be? “It would be nice to name it after my wife, Fíona, who has put up with my nocturnal habits for many years and supported me solidly throughout. She really deserves it,” said Dave.

As it happens, Dave already has an asteroid named after him. So, what a nice thought — asteroids Dave and Fiona circling the sun together for the next few billion years..