Bright Fireball Observed by Many

The fireball of 10th October 2010 as imaged by one of the Armagh Observatory cameras at 02:32 am.

Armagh Observatory received many telephone and internet reports from members of the public regarding sightings of a bright meteor or fireball which crossed over Northern Ireland in the early morning of Sunday, 10th October. The event occurred at 01:32:56 UTC (02:32:56 am BST).

A meteoroid (i.e. a piece of a comet or asteroid), approximately the size of an orange, entered the atmosphere somewhere above NW Ireland at an estimated speed of 20 to 30 kilometres per second. Friction with the Earth's atmosphere caused the meteoroid's surface layers to evaporate and glow, producing a bright meteor in the sky. Upon reaching denser air, the meteoroid began to disintegrate, producing bright flares as bright as a first quarter moon that lit up most of the sky and probably also illuminated the ground.

At the same time, a brightly luminous trail of material, intensely green due to magnesium and iron from the meteoroid, was left behind. The meteoroid burnt itself away completely at an altitude of approximately 70 to 80 kilometres above the ground. The event lasted several seconds and was captured by the Armagh Observatory meteor cameras, which have been recording meteor activity on the night sky since 2005.

It is impossible to say with certainty where the meteoroid came from, but its speed and direction of travel suggest that it may have been a fragment of comet 21P/Giacobini-Zinner. This is a member of the so-called Jupiter family of comets that orbit the Sun with relatively short orbital periods of less than about 20 years. Comet 21P/Giacobini-Zinner has an orbital period of 6.6 years. Its dust-and-ice nucleus is believed to be around 2 km in diameter.

The material shed by the comet every time it swings by the Sun produces a meteor shower known as the Draconids, which peaks in activity towards the end of the first week of October. The meteor shower is interesting because it has been responsible for a number of major outbursts in meteor activity during the 20th century, comparable to or even higher in intensity than the famous Leonid storms. Another outburst is expected in the evening of the 8th October 2011, when the Draconid meteors (so called because they appear to emanate from the head of the constellation Draco, "the Dragon") are expected to reach a rate of up to 500 per hour, causing a display in the sky that is expected to last for at least an hour.

FOR FURTHER INFORMATION PLEASE CONTACT: Apostolus Christou or John McFarland at the Armagh Observatory, College Hill, Armagh, BT61 9DG. Tel.: 028-3752-2928; FAX: 028-3752-7174; aac at sign arm.ac.uk; jmf at sign arm.ac.uk.

Some sightings of the fireball from our Fireball Reports page

Time_of_Sighting: Approximately 2.35 am

Date_of_Sighting: 10 October 2010

Location_of_Sighting: Richhill

Account: I was driving on the main Armagh/Portadown Road travelling towards Richhill when the sky in front of me was lit up by a couple of very bright flashes of light which were followed by a trail of white light. The trail of light travelled from the direction of Richhill towards Markethill. I had to look up to see the trail of light after the flashes. The flashes of light were very bright as I thought they were sheet lightning and the trail of light was also very bright but not as bright as the flashes. The trail of light was visible for approximately 5 seconds and I saw it travel less than half way across the sky. I saw it fading away to nothing, nothing appeared to fall off it and it did not appear to break up.

I know of two other people (my daughter and her boyfriend) who saw the flashes of light in the sky and the trail of light. They were travelling from Redrock towards Hamiltonsbawn and they said the trail of light appeared to be travelling towards Markethill from Richhill.

Time_of_Sighting: 0132 UTC

Date_of_Sighting: 10/10/2010

Location_of_Sighting: Glenshane Pass

Account: A bright green light lit the interior of my vehicle over the course of about one second, originating from above front and terminating to above right (I was travelling in a roughly south easterly direction) and terminating abruptly with a brighter green flash. On looking out of the side window I observed a luminescent pale green trail against the stars, (like a moonlit aircraft contrail but there was no moon) from approximately overhead to approximately 45 degrees elevation travelling on a track from north to south. The trail faded over approximately 20 seconds.

Last Revised: 2010 October 15th