‘We’re due another asteroid strike around now’
“There’s so much to see in the night sky if you take the time to look. In Mayo last year, I had my first sight of noctilucent clouds. A relatively new phenomenon, these are exceptionally bright, wispy clouds made of ice crystals that are visible only in twilight. The International Space Station frequently whizzes through our skies like a shooting star, and in Dark Sky areas you can regularly see meteor showers as spectacular as any fireworks display.”
Dark Sky Preserves (DSPs) are designated by the International Dark Sky Association as areas where artificial light pollution is restricted and people can appreciate the quality of the dark night sky. Ireland has two such designations, the Dark Sky Park in Mayo – which celebrates its annual Dark Sky Festival on 2-4 November next – and the Dark Sky Reserve in Kerry.
“Almost half of the population of Ireland live in areas where artificial light is so bright that the Milky Way can’t be seen,” says Professor Brian Espey. “Dark Sky is a precious commodity and one that can promote sustainable tourism. The preserves we’ve got fit very well with the Wild Atlantic Way, and encourage off-season visitors, so the tourist potential is great.”
Dublin is far from Dark Sky territory, but that hasn’t stopped amateur astronomer David Grennan making some significant discoveries from the back garden of his home in Raheny. An IT analyst with CIE, he has discovered three supernovae and two asteroids using a high-spec telescope he built himself. He named one of the asteroids after his late mother, Catherine Griffin.
“One of my earliest childhood memories is craning my neck in the back garden looking up at the night sky, and instead of urging me to come in out of the cold, my mother brought me a coat to wear,” he says. “Few people have a threekilometre memorial stone orbiting between Mars and Jupiter named after them, but I did it to honour her.”
Apart from making inter-galactic discoveries from his back garden observatory, David spends much of his spare time tracking Near Earth Objects, space rocks that have the capacity to pose a real threat to the planet.
“It’s not a question of if, but when a major asteroid will strike,” he says. “It could be 100 years or 10,000 years from now, but on average an asteroid hits Earth every 65 million years. It’s been that long since the one that killed the dinosaurs, so in cosmic terms, we’re due another one around now.”
It may seem like the stuff of science fiction, but David suggests that, because asteroids are usually heavy in iron, it would be prudent to employ technology using a magnet to change the trajectory of such an object.
“It would take the resources of all the major superpowers combined to develop such technology, but they’re not doing it,” he says.
For now, however, there is no threat to our beautiful planet, only the promise of a dazzling event to light up the night sky, making this Friday a marvellous night for a moondance.