One of the world’s most famous and stunning solar phenomena is eagerly expected over Irish skies in the coming weeks, stargazers have said.
The celebrated Northern Lights, also known as the Aurora Borealis, has its best chance of being seen in more than a decade because of a peak in the sun's activity.
The celestial light show appears as ghostly, wispy rays of greenish and whitish colours dancing across the heavens.
Brendan Alexander, an astronomer in Co Donegal, said the further north and away from city lights people are, the better chance they have of seeing the dream-like spectacular.
“It’s definitely worth seeking out,” he said. “It’s an event that - especially on these shores - is so rare. But we are lucky to live just north enough to experience it - any country further south than us won’t be able to see it.”
The sun has a “heartbeat” every 11 years or so — known as the solar cycle — and when it erupts, charged particles blast into space and are sucked into the North Pole.
These explosions react with the earth’s atmosphere, sparking great swathes o coloured light over the night skies, known for centuries by native north Americans as the Dance of the Spirits.
The long, clear darkness of winter is among the most likely times to see it and astronomers believe the sun will hit the peak of its cycle again in the coming year.
Between now and the equinox in March is being tipped as the best opportunity in Ireland for more than ten years.
“It is really captivating, just the sheer strangeness of it means it’s worthwhile seeking it out,” said Mr Alexander, who saw the phenomenon for the second time from the Donegal coast last March.
The postgraduate, who is studying for a Research Masters Degree in Science at Letterkenny Institute of Technology, said observers should give their eyes about 20 minutes to adapt to the dark.
Then they should look towards the northern horizon for a whitish or greenish dome of light.
“From time to time you will see rays shoot up from the dome of light, across the horizon, and if it gets really active you can see the rays moving across the base of the dome, and they can shoot right up to the centre of the sky,” he said.
“When you are watching the display it’s very eerie, almost alien. It’s like nothing you have seen before.”
Mr Alexander, who was shortlisted for the BBC Stargazing Live’s astronomy photographer of the year contest, issues free alerts on expected sightings through his www.donegalskies.com website.