Science

It's once again time for the Perseids, one of the best meteor showers of the year

Each August, Earth plows through a thick trail of debris left over from a passing comet. The result: A spectacular night of meteors lighting up the sky.

Full moon will make it more challenging but not impossible to catch a ‘shooting star’

A Perseid meteor streaks across the Milky Way over the Saskatchewan Summer Star Party in southwest Saskatchewan at Cypress Hills Interprovincial Park, a Dark Sky Preserve. (Submitted by Alan Dyer/AmazingSky.com)

Each August, Earth plows through a thick trail of debris left over from a passing comet. The result: A spectacular night of meteors lighting up the sky.

One of the best and most anticipated meteor showers of the year is the Perseids, which takes place from mid-July to the end of August. But peak viewing — where you'll get a chance to see the most meteors — falls on the night of Aug. 12-13 this year, according to the International Meteor Organization. 

That's when Earth moves through the thickest part of the debris left over from comet 109P/Swift-Tuttle, with tiny pieces of particles burning up in our atmosphere at 59 km/s.

Try this interactive map showing how Earth passes through the meteor shower:

Swift-Tuttle, which was first discovered in 1862 independently by both Lewis Swift and Horace Tuttle, makes an orbit of the sun every 133 years. The last time it was in our solar system was in 1992. Still, from all those trips around the sun, it's left behind plenty of debris. 

Some of this debris can be bigger than the normal grain-like particles and can create beautiful bolides, or bright fireballs that light up the sky.

How to see the meteors

Though the Perseids rarely disappoint, there is one thing to contend with this year that may hamper your viewing delight: the full moon.

With the moon lighting up the sky, that means that only the brightest of meteors will be visible. Fortunately, many Perseids tend to be quite bright anyway. 

The Perseids are given their name for the constellation — Perseus. This is the point in the sky from which they seem to appear, called the radiant.

A chart of the sky showing constellations that include Perseus, from which streaks appearing to radiate.
This map shows the radiant of the Perseids, which get their name name from the nearby constellation Perseus. The radiant is the point in the sky from which the meteors seem to appear. (American Meteor Society)

While some people like to look in the direction of the constellation, which rises in the northeast, it limits the number of meteors that can be seen, since they will have shorter tails. To see longer meteors (ie., with long tails), you don't need to look directly up, but at more of an angle.

And the best thing about meteor showers is that you don't need a telescope or binoculars, just your own eyes.

You can also keep an eye out for "earthgrazers," meteors that skim Earth's atmosphere and, as a result, leave a long trail behind them.

These are best viewed early in the night, when the sky is dark and the radiant is low in the east. They will be moving roughly from north to south.

To increase your chances of catching some bright meteors, you could head out ahead of the peak night of Aug. 12, or even in the days after, when the moon won't be entirely full. Try to keep the moon behind you when stargazing to block out its glare. 

Helpful hints

Another hot tip is to try to lie down on a blanket or even on a beach lounge chair, otherwise your neck will get tired and ache from trying to look up. 

Also, put away those phones as your eyes will need to become accustomed to the dark, something that can take anywhere from 30 minutes to an hour. And remember, the more stars you can see, the more faint meteors you will catch, so try to get to as dark a location as you can, away from city lights.

Patience is your friend, so try not to give up if you haven't seen any meteors within a few minutes. Under ideal conditions, the Perseids can produce more than 100 meteors an hour, but don't expect to see that many. 

At this time of year, you can also catch a couple of planets: Jupiter will be low in the east and hard to miss, and Saturn will lie in the southeast.

People can also use free apps like StarWalk or SkyView (they have a night mode that displays in red in order to preserve your night vision) that allow you to hold your phone up to the sky to identify constellations, planets and more.

There's always something to look at in the night sky, even if meteors aren't providing a show.

ABOUT THE AUTHOR

Nicole Mortillaro

Senior Science Reporter

Based in Toronto, Nicole covers all things science for CBC News. As an amateur astronomer, Nicole can be found looking up at the night sky appreciating the marvels of our universe. She is the editor of the Journal of the Royal Astronomical Society of Canada and the author of several books. In 2021, she won the Kavli Science Journalism Award from the American Association for the Advancement of Science for a Quirks and Quarks audio special on the history and future of Black people in science. You can send her story ideas at nicole.mortillaro@cbc.ca.