Five Things to Know about the Perseid Meteor Shower
By Graham Jones. Published 31-Jul-2024
The Northern Hemisphere’s summertime shooting-star display peaks around August 11 to 13.
The brief, bright streak of a Perseid meteor is produced by a tiny particle hitting Earth’s atmosphere at enormous speed.
©Unsplash/Tengyart
Get Ready for Another Cometary Show
Once a year, as it orbits around the Sun, Earth passes through a trail of debris left by a comet called Swift-Tuttle.
When this comet debris enters Earth’s atmosphere, it produces a shower of meteors: brief streaks of light in the night sky, up to 100 per hour around the peak.
Here are five things to know about the annual display of shooting stars known as the Perseid Meteor Shower.
Go to our Interactive Sky Map for the Perseids
1. Always around the Same Time of Year
All meteor showers peak around the same date from one year to the next.
In the case of the Perseids, the peak date is around August 12. So, for skywatchers in the Northern Hemisphere, the Perseids come in the middle of summer, and generally during school holiday time.
The big variable—apart from the weather—is the Moon phase. If the peak falls close to the date of a bright Full Moon that shines all night long, the number of observable meteors is reduced.
In 2024, the Moon phase is fairly good for the Perseids: it will be a First Quarter Moon. In other words, it will be a Half Moon that sets around midnight.
2. Tiny Particles but Enormous Speeds
The trail of debris left by comets consists of small particles of dust. The size of the particles typically ranges from around 0.1 millimeters (0.005 inches) to a few centimeters (an inch).
How do these small particles produce such bright streaks of light? It’s because they hit Earth’s atmosphere at extremely high speeds—around 60 kilometers per second (40 miles per second).
The Perseid Meteor Shower normally produces a high level of activity around its peak. Under ideal conditions, an observer could expect to see approximately 100 meteors per hour. In practice, however, the observed rate is less than this.
3. Every Meteor Shower Has a Radiant
This composite image was produced by combining photos of 18 different Perseid meteors. The streaks appear to originate from the same area of the sky.
©iStock.com/Jerry Hamblen
Every meteor in a meteor shower appears to come from the same area of the sky, called the radiant.
For the Perseids, the radiant lies in the constellation Perseus—which is why they’re called the Perseids.
Although shooting stars appear to travel in different directions away from the radiant, this is a result of our perspective. In reality, all of the dust particles are traveling parallel to one another as they enter Earth’s atmosphere.
It’s a bit like looking up into a shower of rain. The raindrops appear to fan out from a central point, with some going to the left, others to the right. In actual fact, all the raindrops are falling from the sky in straight parallel lines.
4. The Higher the Radiant, the Better
It is not necessary to look toward the radiant to enjoy a meteor shower, since shooting stars can appear in all parts of the sky.
However, knowing how high the radiant is can be helpful: the higher the radiant above the horizon, the more meteors you are likely to see.
Over the course of a night, the position of the radiant appears to move as the Earth rotates. Generally speaking, around August 12, the constellation Perseus rises during the night, and reaches its highest point in the sky in the morning.
Therefore, the best time to see Perseid meteors tends to be before dawn—but when the sky is still dark.
Twilight and sunrise times for your town or city
In the Southern Hemisphere, where August 12 is the middle of winter, Perseus doesn’t climb far above the horizon—or doesn’t appear at all, the farther south you go. For this reason, the Perseid Meteor Shower favors observers in the Northern Hemisphere.
5. The Perseids Are Happening Now!
The Perseids peak around August 12, but Earth begins encountering comet debris from Swift-Tuttle a few weeks before then.
Overall, the Perseid Meteor Shower is active from around July 17 to August 24. This means you might be able to catch Perseid shooting stars anytime now.
Go to our Interactive Sky Map for the Perseids
timeanddate’s Interactive Sky Map for the Perseids shows the movement of the radiant over the course of a night—you can change the date with the Select night drop-down menu above the map on the right.
Hour-by-hour information is also summarised in the What time is the meteor shower tonight table below the map.
Here, our Interactive Sky Map shows the position of the radiant as seen from New York at 23:00 (11 pm) local time on August 11, 2024. In this example, the altitude—the angular distance of the radiant above the horizon—is 22 degrees and rising.
©timeanddate.com