13 August 2015
The mesmerising Perseid meteor shower is set to light up skies across the world tonight, including South Africa, as the annual celestial event reaches its peak this week. While the shower might not be as visible in urban areas compared to rural areas, if you are in any wide open space with a good view of sky after midnight, you might be in for a great cosmic show.
“It is a northern hemisphere constellation, but we can see the Perseid from South Africa relatively from the northern horizon,” Astrological Society of Southern Africa Johannesburg Centre chairperson and viewing officer Jerome Jooste told News24 yesterday.
Perseid, derived from the Greek word for ‘son of Perseus’ (the hero-god) is the debris cloud from the orbit of the comet Swift-Tuttle travelling past Earth on its way back to the Perseus constellation, part of the Milky Way, located 250 million light-years from Earth.
The meteor shower seen from Earth is distinctive in the variety and beauty of its formations. While the show is best viewed in the northern hemisphere, stretching from Asia to the Americas, over Europe, Africa will be able to view the tail end of the event, itself a sight to behold, according to local astronomers.
The radiant of a meteor shower is the point in the sky, from which meteors appear to originate. The Perseid shower radiates from a point within the constellation of Perseus. “What we call the radiance or the point of radiance, where the meteors seem to radiant from is a little higher than the Perseid constellation itself,” Jooste says, “you will start to notice there will be more meteors than what you would normally see and also there would be more per an hour.”
Most of the Perseid meteors will burn up as close as 80km above sea level, within Earth’s outer atmosphere, producing long bright trails and fireballs, before becoming part of the larger cosmic debris.
No special equipment or specialist astronomical knowledge is needed to view Perseid, as much of the action is easy to find with the naked eye. The only requirement is find a dark, open spot where as much sky, particularly to the north, is viewable. The show will be late and intermittent – the meteors arrive in spurts with a bit of waiting time between sightings – so a cup of coffee, a comfortable chair and some patience will make the experience more enjoyable.
The more open the sky, the better, as there is much to view, with meteors moving in different directions and at varying speeds. The current waning crescent moon also helps keeping the sky as dark as possible for the best viewing experience.
The Perseid meteor shower has been recorded for thousands of years, first documented in China in AD 36. Its origin was officially tracked and the shower named by Belgian astronomer Adolphe Quetelet in 1835. Catholics refer to the shower as the ‘tears of Saint Lawrence’, occurring around the same date as the saint’s martyrdom. The Romans believed that the meteor shower was a positive harvest forecast from the fertility god Priapus.