Even the experts disagree on the magnitude of next week's Leonid meteor shower, but local astronomical societies are gearing up for the event with lectures to inform the public on the occurrence and what they might be able to see in the skies.
Dr David Asher of Armagh Observatory, an expert on meteors, told Dublin listeners at a Science Week Ireland lecture last night that the Leonid meteor storm in 2001 and 2002 should be spectacular, but next week's has some potential.
The Leonid meteor shower is the result of the Earth passing through the dust trail left by Comet Tempel-Tuttle. The meteoroids follow the solar orbit of Comet Tempel-Tuttle, which crosses the Earth's orbit around November 17th of each year.
A heavy meteor shower, when bright blue and green meteor trails can be seen, occurs approximately every 33 years when Earth passes through the thickest part of the meteoroid swarm. The Leonids are so named because they appear to come from the direction of the constellation Leo.
A Leonid shower in 1966 filled the sky with tens of thousands of shooting stars for several hours, Dr Asher said, but this year's is not expected to last more than one hour.
The best guess for this year's shower is 2 a.m. on November 18th.
The sight is extremely unpredictable, according to Mr John O'Neill of the Irish Astronomical Society. "It may or may not be an intense shower of shooting stars," he said.
"We need to be lucky on all fronts. Both the weather [to create a clear sky for ideal viewing conditions] and the meteors must co-operate."
The most spectacular part of last year's shower occurred 16 hours earlier than expected, according to Mr David Moore, chairman of Astronomy Ireland, another amateur astronomy society. "The experts were wrong last year, so we will be watching the skies on the 16th, 17th and 18th," he said.
Mr Moore said the meteors would be visible in all parts of the sky. "It's not necessary to focus in any direction," he said. "They appear all over, and we think this year there will be a good scattering of meteoroids of varying brightness."
Meteor storm watches sponsored by Astronomy Ireland and open to the public will occur at eight locations around the State on November 17th, beginning at 10 p.m.
The locations are: Dublin: Papal Cross, Phoenix Park; Galway: Westside Shopping Centre; Cork: Ballyphehane Community Centre; Castlebar: Ballyvary Central School; Ballina: Horseman Viewing Bay; Lisburn: Astronomy Shop in Longstone Street; Mullingar: St Coman's GAA Club; Tipperary: Ballykisteen Golf and Country Club.
Shower-watching sites in Clonmel and New Ross are on private land. Mr Moore said interested participants can ring (052) 21892 for directions to the Clonmel site and (087) 683-6824 for directions to New Ross.
The celestial fireworks may not arrive until 2 or 3 a.m., but storm-watchers can use telescopes brought by the society (for a £1 donation) to look at other marvels in the sky.
Mr Moore said that Jupiter and Saturn in particular would be highly visible as they would appear higher in the sky than they have been for some time.
Members of the Irish Astronomical Society are heading to the Wicklow Mountains to try and catch the celestial action. Mr O'Neill said it was possible to capture the meteors on film if you had a camera on which you could leave the shutter open for 30 minutes or more.
Dr Asher's Science Week lecture on the Leonids will be repeated on November 15th at NUI Galway at 8 p.m. and on November 16th at the Ballyphehane Community Centre in Cork at 8 p.m.