"Respect the darkness."
That's the advice of Malcolm Park, president of the North York Astronomical Association and co-ordinator of its annual Starfest, which takes place Aug. 12-15 northwest of Toronto.
He's talking about the total absence of white light - interior or exterior vehicle lights, flashlights, camera flashes. Everything that glows needs a red filter during the weekend campout under the stars, as city dwellers step out of their artificially lit environment to experience what is expected to be a dazzling spectacle.
"The timing this year is excellent because the Perseids meteor shower peaks on Aug 12," Mr. Park says. Predictions put the peak rate at 200 meteors a night - "quite the frequency," he says with understatement.
It takes the human eye about half an hour to adjust to the kind of darkness that they're trying to achieve, which can be ruined with one rogue light.
"Picture hundreds of tents, people tinkering with telescopes in complete darkness. Some stars are very bright, and they vary in duration," he says, but every falling star inspires awe, and "hundreds of people gasp in unison."
The event is part of a growing number of "star parties" that take place across North America and Britain during the summer. The weekend get-togethers often feature talks by scientists (astronomer René Doyon will speak at Starfest about the James Webb Space Telescope) as well as family activities, such as building your own telescope.
But you don't need a telescope to experience the spectacle at Starfest, which started out as a gathering of friends 29 years ago and now attracts up to 1,000 visitors - including plenty of kids.
"Astronomers tend to be geeks. It's a rude shock, I know. But geeks have families too," says Tony Ward, who has been attending for 25 years. Mr. Ward grew up in New Zealand, accustomed to rural landscapes and dark skies. "I realized what I've experienced is very rare. We've lost that sense of wonder when we look up at the sky, it's blotted out by urban light pollution. There are people who've never seen the sky as it is."
Starfest is known outside Canada too; in 2007, it was ranked among the world's top 10 such events by the BBC's Sky at Night magazine - up there with similar celebrations in Australia, Switzerland and the Grand Canyon.
Mr. Ward says the coolest thing he has ever seen at Starfest is a bolide, an exceptionally bright meteor that can make daylight appear for an instant in the dark. "I was about to go to sleep, and it came from behind me. It was like a flash blasted my image to the floor of the tent."
Of course, this doesn't happen every year.
"But it will happen again, somewhere in the world," Mr. Ward says, "and there's always that feeling in the back of your mind that it will happen again to you."
While Starfest does not take place in what is known as a dark sky preserve, the organizers have an understanding with the owners of the venue, River Place Park in Ayton, Ont., that surrounding houses black out their lights during the viewing nights.
A dark sky is no easy feat, says Rita Gordon, co-owner of Gordon's Park on Manitoulin Island in Lake Huron. She was able to have the park designated a dark sky preserve by the Royal Astronomical Society of Canada after meeting a long list of requirements. They include letters of support from surrounding municipalities and three independently conducted darkness readings (called sky quality meter readings).
Gordon's Park is one of eight dark sky preserves in Canada, she says, with one of the highest sky quality ratings, an average of 21.93 out of 23.
"You might reach 23 in the middle of the ocean," says Ms. Gordon, who will host the annual Manitoulin Star Party on Aug. 6-9 and also holds Thursday-night viewings through the summer.
Katrina Ince-Lum, a massage therapist from Toronto, has been attending star parties for 10 years. "They're addictive," she says. Ms. Ince-Lum is drawn in for the socializing as much as the skies. She calls her favourite moment, "kind of a cliché. But I'll never forget the first time I saw Saturn through a telescope. With the rings, there's nothing else it could be."
If you can spare a little reverence for the darkness, everyone is welcome at Starfest, Mr. Ward says. "There's more than enough sky to go around."