Look to the sky Monday night and you might be treated to the sight of the Swift-Tuttle comet’s spectacular space show.
Every year around August the Earth intersects with the comet’s path and grain-sized debris hit Earth’s atmosphere, streaking across the night’s sky, appearing to come from the direction of the Perseus constellation and creating what’s called the Perseid meteor shower.
“A meteor shower basically is a whole lot of meteorites – what we call shooting stars – little pieces of material from space that falls through the atmosphere and basically burns up,” said University of Victoria astronomer Karun Thanjavur. “A shower happens when you have many of them happening simultaneously and this is because the Earth’s orbit passes through debris that is left behind by a comet.”
This month, that comet is the Swift-Tuttle.
When it orbits the sun, the Swift-Tuttle heats up, releasing debris like ice and dust, which form its tail. The debris follows along with the comet’s orbit and intersects with Earth’s every August.
“It’s not as if the comet is there right now, it’s just that at some point in the past it passed that place,” Thanvajur explained. “As the earth passes through that point, there is more debris there that enters the atmosphere and burns up, so that’s why we have this sudden increase in shooting stars or meteorites.”
Thanjavur recommends finding a dark spot to watch, so that even the smaller meteors are visible.
“It only lasts a few seconds as each meteorite burns out. All you need to do is lie back and look at the sky,” he said. “These are events that you don’t need any special equipment for. You don’t need a telescope…all you do is just look up at the sky and if you’re lucky, you’ll see these really bright ones…and then at other times it will be fainter.”
Astronomers predict that the night of Aug. 12 will be the best time to watch the showers. Oak Bay’s Cattle Point is a dark-sky preservation area and a great space for inner-city night sky watching.
“It’s something for everyone to enjoy,” Thanvajur said. “It’s the sky putting on a show.”