Fireball streaks across Northern Ireland skies

Image caption,
Comet 21P/Giacobini-Zinner is thought to be the source of the fireball

Anyone making their way home from traditional Saturday night entertainments at the weekend may have thought the bright fireball streaking through the skies above them was a sign of having too much of a good thing.

The cause was actually a meteoroid, an orange-sized piece of a comet or asteroid, burning up over Northern Ireland early last Sunday.

The ball entered the atmosphere above the north west at an estimated speed of 20 to 30 km per second at about 0232 BST.

Armagh Observatory received many telephone and internet reports from members of the public reporting sightings of the meteoroid.

Scientists at the observatory said that, due to the object's speed, friction with the Earth's atmosphere caused its surface layers to burn off, producing a bright light in the sky.


As it entered further into the atmosphere, denser air caused it to begin to disintegrate, producing bright flares which lit up most of the sky and may also have illuminated the ground.

A luminous trail of material, vivid green due to magnesium and iron in the meteoroid, was briefly left behind in the sky.

The object completely disintergrated at about 70 to 80 km above the ground.

The whole event only lasted several seconds and was captured by the Armagh Observatory meteor cameras, which have been recording meteor activity on the night sky since 2005.

The scientists said that the speed and direction of the meteoroid suggest it may have been a piece of a comet called 21P/Giacobini-Zinner.

This comet orbits the sun every six and a half years. Its dust-and-ice nucleus is believed to be about two 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.

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