The Perseids Meteor Shower
August sees the return of the most reliable meteor shower of the year, the Perseids, with rates of shooting stars possibly increasing to dozens every hour, depending on how dark and clear your skies are, and what time of night you’re out. Steve Owens, astronomer at Glasgow Science Centre, and author of Stargazing for Dummies explains how best to plan a meteor-watching trip.
The Most Reliable Meteor Shower of the Year
Look up for long enough on any clear, dark night and you’ll see a shooting star. These beautiful flashes of light in the sky – also known as meteors – are in fact not stars at all, they’re tiny bits of space grit burning up in our atmosphere.
For most people shooting stars are rare events but under dark skies you can expect to see a few meteors on any clear night. From towns and cities, under light polluted skies, you can’t see many at all. Those rare meteors which are bright enough to outshine our streetlights often go viral on social media, but by the time you read about them or see shaky videos of them they’re gone. Blink and you’ll miss them.
But there are certain times of year when your chance to see shooting stars dramatically increases, during what we call meteor showers.
Our solar system is full of debris, the leftovers of the formation of the planets. As the Earth orbits the Sun it hoovers up any of this debris that gets in its way. There are places in space where this debris clumps together, and when Earth enters one of these denser regions the amount of debris – and therefore the number of shooting stars – increases.
Mark your calendar
On the night of Saturday 12 August into Sunday 13 August 2023 Earth will pass through the densest part of a dust cloud left behind by Comet 109P/Swift-Tuttle, causing the peak of the Perseids meteor shower. You can begin watching for Perseid meteors now, and the shower will last until late-August, but the peak of the shower occurs overnight on 12/13 August.
The best time of night to watch the Perseids meteor shower is from around 10:30pm onwards on 12 August. The later you observe, the more meteors you’ll see. The wee small hours before dawn are best.
The number of meteors that you will observe every hour depends on a range of factors: the density of the dust cloud that the Earth is moving through; the time of night you’re observing; the fraction of your sky that is obscured by cloud; and the darkness of your sky.
This year the Perseid meteor shower has an expected maximum rate of around 150 shooting stars per hour. This is the number of meteors that you can expect to see each hour if you’re out at exactly the right time with exactly perfect sky conditions.
However, conditions are rarely that perfect. You might not have clear skies. If the sky is half covered in cloud, you’ll only see half of all the meteors. If you’re in or near a town or city the light pollution will drown out most of the rest of meteors.
Preparing for the Show
But if the forecast looks good, it’s really worth the effort to head outside somewhere dark and watch one of nature’s most spectacular events. Scotland has many great places for dark sky meteor-watching. You could head to Galloway Forest Dark Sky Park to see some of Scotland’s darkest skies, but really any effort you can make to get away from city lights will help.
Meteors streak across the whole sky so you don’t need to look in any specific direction, but of course if you’ve got a tall building or tree that’s blocking the view, or a streetlight nearby that’s a bit glare-y, then put these to your back.
You don’t need any special equipment to observe a meteor shower; just your eyes. You’ll hopefully be out for a good long time enjoying the celestial show, so best to get comfortable. You might want to bring a reclining deck chair with you. Just lie back, wrap up warm, take in as much of the sky as possible, and be patient. The longer you spend looking up the better your eyes will adapt to the darkness. Popping in and out of the house or car to have a look just doesn’t work.
Let’s keep our fingers crossed for clear skies, and when we see our first Perseid meteor, let’s wish upon it for lots more clear skies to come.
This blog post by Steve Owens is adapted from an article by Glasgow Science Centre that first appeared in Glasgow Times in August 2023.