One of the best shows in the night sky is coming up next week. The Perseid meteor shower peaks on Wednesday night, and this year it is not to be missed!

Right now, as Earth travels along its orbit around the Sun, the planet is passing through a stream of debris left behind by a comet known as 109P/Swift-Tuttle. This comet only passes through the inner solar system once every 133 years or so. However, each year we are treated to a reminder that it’s out there, as Earth sweeps up the bits of icy debris it leaves behind on each pass. When these tiny bits of ice and rock plunge into the atmosphere, they produce the streaks of light we call the Perseid meteor shower.

In this 30-second exposure taken with a circular fish-eye lens, a meteor streaks across the sky during the annual Perseid meteor shower on Friday, Aug. 12, 2016, in Spruce Knob, West Virginia. Photo Credit: (NASA/Bill Ingalls)

According to the International Meteor Organization (IMO), under ideal conditions, observers typically see anywhere from 50-75 meteors per hour during the Perseids peak, which occurs around the 12th of August every year. Sometimes, this shower can deliver as many as 100 meteors per hour or more.

The Perseids radiant — where the meteors appear to originate from — is located in the northern sky, near the constellation Perseus. It never sets below the horizon at this time of year. So, rather than having to wait for the radiant to rise during the night, we can start watching for Perseids as soon as the Sun has completely set.

The location of the Perseids radiant at around midnight on August 11-12. Credit: Stellarium/Scott Sutherland

Even now, a week before the meteor shower peak, viewers can see perhaps 10-20 Perseids per hour throughout the night. The peak on August 11-12 is the absolute best night to watch. If skies are cloudy that night or the timing isn’t good, NASA says that the most likely time to see meteors, otherwise, is a couple of days on either side of the peak.

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Whatever night you get out to watch, the best time to see the Perseids during the night is usually in the hours between midnight and dawn. That is when the sky tends to be the darkest. Also, the meteor shower radiant is high in the sky at that time, which means that we are looking more or less straight into the path of the meteoroid stream.

This graph shows the average Perseid meteor activity from 2014-2020. Credits: Graph and background image courtesy NASA

This year, viewing will likely be better than we’ve seen for the past few years, due to the Moon. With the shower peaking only a few days after the New Moon, there will only be a thin crescent Moon in the sky that night, which will set just a few hours after nightfall. This will leave behind a nice dark night sky, which will make it easier for us to see the show!

Read on for tips on how to get the most out of watching a meteor shower.

WHAT’S GOING ON HERE?

Meteor showers happen when Earth encounters a stream of ice, dust, and rock left behind from a comet (or sometimes a special kind of asteroid). As Earth sweeps through the stream, the bits of debris plunge into the planet’s atmosphere, travelling anywhere from 54,000 to 255,000 kilometres per hour. At that speed, these meteoroids compress the air molecules in their path, squeezing them together until they glow white-hot.

The bigger the piece of debris, the brighter and longer-lasting the meteor will be.

Watch below: Dozens of Perseid fireballs captured by NASA in 2020

Click here to view the video

The Perseids occur every year between July 17 and August 26, as Earth passes through the stream of debris from Comet Swift-Tuttle. 109P/Swift-Tuttle was last seen in the inner solar system in 1992. Right now, it’s far out in the solar system, near the orbit of Neptune, and still headed even farther out. It will return in late 2125.

METEOR? METEOROID? METEORITE?

The bright streaks seen from these showers are called meteors.

A meteoroid is a piece of dust, rock or ice floating through space, left over from the formation of our solar system. The smallest – only a few millimetres wide – tend to be called __micrometeoroids. Anything larger than a metre in diameter is usually called an asteroid.

A primer on meteoroids, meteors and meteorites. Credits: Scott Sutherland/NASA JPL (Asteroids Ida & Dactyl)/NASA Earth Observatory (Blue Marble)

The more massive an object is as it enters Earth’s atmosphere, the brighter the resulting meteor will be. The brightest are called fireballs, while a fireball that ends with an explosion is known as a bolide.

Some fireballs and bolides result in bits of the meteoroid reaching to the ground. When these are found, they are called meteorites.

Related: Got your hands on a space rock? Here’s how to know for sure

SPECTACULAR PERSEIDS

The Perseids are one of the strongest meteor showers of the entire year, and this alone makes it worth watching. However, there are two other ways this meteor shower distinguishes itself.

First, it has the most fireball meteors of any annual shower.

In the Royal Astronomical Society of Canada’s Observer’s Handbook 2021, Philip McClausland writes “Fireballs are exceptionally bright meteors that are spectacular enough to light up a wide area and attract public attention.”

Watch below: An all-sky camera captures a brilliant Perseid fireball

Click here to view the video

The second is the ability of some Perseid meteors to leave behind a phenomenon known as a persistent train.

Meteors typically flash for a second and are gone. Fireballs can last up to 10 seconds. Every once in a while, though, a meteor will leave behind a trail of glowing ‘smoke’. These can remain visible for up to several minutes or possibly for more than an hour.

Spotting persistent trains is pretty common, depending on the meteor shower. They have only rarely been recorded, though. Studies of them go back decades, but there is little hard evidence to study the phenomenon. Still, scientists have narrowed their cause to one of two likely reasons: ionization or chemiluminescence.

Ionization means that an atom or molecule gains or loses electrons and thus takes on a negative or positive charge. In the case of a persistent train, a fast-moving meteoroid strips away electrons from air molecules along their path. When these ionized molecules pick up a stray electron to balance out their charge, they release a small burst of light.

Chemiluminescence is the production of light through a chemical reaction. When metals like iron and nickel vaporize off the surface of a meteoroid, they can chemically react with ozone and oxygen to produce a glow. Since these processes take much longer than the original meteor flash, the train can persist for some time after the flash goes out.

Watch below to see a persistent train produced by a December Geminids meteor

One of these explanations may account for these glowing trains, or both may cover different occurrences, at different times, and even between individual meteors. It will apparently take more sightings and recordings of this phenomenon to explain them fully.

Related: Want to find a meteorite? Expert Geoff Notkin tells us how!

TIPS FOR WATCHING A METEOR SHOWER

Here is an essential guide on how to get the most out of meteor shower events.

First off, there’s no need to have a telescope or binoculars to watch a meteor shower. Those are great if you want to check out other objects in the sky at the same time — such as Jupiter and Saturn, which are up all night these days. When watching a meteor shower, though, telescopes and binoculars actually make it harder to see the event because they restrict your field of view.

Here’s the three things needed for watching meteor showers:

• Clear skies,

• Dark skies, and

• Patience.

Even a few hours of cloudy skies can ruin an attempt to see a meteor shower. Since the weather is continually changing, be sure to check for updates on The Weather Network on TV, on our website, or from our app.

Living in cities makes it very difficult to see meteor showers. Those living in suburban areas, with dark back yards shielded from street lights by trees and surrounding houses, may see the brightest meteors. Rural areas offer the best viewing, though, as they are far away from city light pollution.

For most Canadians, simply driving out into the surrounding rural areas is usually good enough to get under dark skies. However, if you live anywhere from Windsor to Quebec City, that will be more difficult. Unfortunately, getting far enough outside of one city to escape its light pollution tends to put you under the light pollution dome of the next city over.

Watch below: What light pollution is doing to city views of the Milky Way

Click here to view the video

In these areas, there are a few dark sky preserves. A skywatcher’s best bet for dark skies is usually to drive north and seek out the various Ontario provincial parks or Quebec provincial parks. Even if you’re confined to the parking lot, after hours, these are usually excellent locations to watch (and you don’t run the risk of trespassing on someone’s property).

Once you have verified you have clear skies, and you have limited your exposure to light pollution, this is where having patience comes in.

For best viewing, give your eyes time to adapt to the dark. Typically, this takes about 30 minutes of avoiding any sources of bright light (includes cellphone screens). Just looking up into the sky during this time works fine, and you may even catch some of the brighter meteors in the process.

Lastly, the graphics presented for meteor showers often give a ‘radiant’ point on the field of stars, showing from where the meteors appear to originate. Meteors can flash through the sky anywhere above your head, though. So, don’t focus on any particular point in the sky. Instead, just look straight up and take in as much of the sky as you can, all at once. Also, since our peripheral vision tends to be better at night, you may be surprised at how many meteors you can catch from the corner of your eye!

For more, visit the websites of the Canadian Space Agency and the Royal Astronomical Society of Canada (RASC).

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