Anyone who gazes at the summer night sky, even for a short time, is likely to spot a few “shooting stars” crossing the sky.
The best meteor display of the summer occurs during the second week of August, during the annual Perseid meteor shower, which at its peak around the nights of August 11 and 12 is capable of producing 50 to 100 fast, bright meteors per hour for a single observer. Many of the blazing meteors with trails are visible under clear skies. 2024 will be a very good year to observe the Perseids, as the bright light of the moon will not interfere.
The very first precursors to the Perseid shower began appearing around July 25. You’ll only see a few per hour at best, but their numbers will start to increase during the second week of August. The last stragglers of the Perseids could still be seen as late as August 18.
In general, Earth experiences more intense meteor activity during the second half of the year. And you’re more likely to see twice as many meteors per hour before dawn than during the evening hours. This is because during the hours before midnight, we’re on the “back” side of the Earth, due to our orbital motion through space.
So any meteor particle generally has to have an orbital speed greater than Earth’s to “catch” us. However, after midnight, when we are facing the “forward” side of Earth, any particle that is along the planet’s orbital path will enter Earth’s atmosphere as a meteor. When such objects collide with our atmosphere at speeds of 11 to 72 km per second, their momentum energy quickly dissipates as heat, light, and ionization, creating short-lived streaks of light commonly called “shooting stars.”
If you want more tips on how to photograph summer meteor showers, check out our guide on how to photograph meteors and meteor showers and if you need imaging gear, consider our best cameras for astrophotography and best lenses for astrophotography.
The extras of the Meteors
In addition to the Perseids, many other smaller meteor showers are active at various times throughout July and August. While the hourly rates of these other meteor showers are only a fraction of the number of meteors produced by the Perseids, they produce a wide variety of meteors of different colors, speeds, and trajectories. Summer meteors, which sometimes pass in front of your field of vision, are particularly visible between late July and the third week of August.
And between July 26 and August 21, no fewer than six different minor constellations are active. Among them are the Capricornids, Delta Aquarids, Piscis Australids, Alpha Capricornids, Iota Aquarids, and Kappa Cygnids.
The radiants of five of these showers peak about midway in the southern sky between 1 a.m. and 3:30 a.m. local time. A radiant is the place in the sky where the paths of the shower members, if extended backward, would intersect near the star or constellation for which the shower is named. Many people mistakenly assume that this is the best place to look for these meteors, but in fact the region of the sky above and to the south is where they are most likely to be seen.
In addition to meteor showers, there are always other sporadic, seemingly unrelated ones, occurring at an average rate of about seven per hour. The duration in days of a shower is somewhat arbitrary, since the beginning and end are gradual and indefinite.
The only equipment you’ll need is your eyes and a little patience.
As one long-time meteor enthusiast once observed: “Meteor watching is relaxing and enjoyable, potentially spectacular, and just plain fun!”
The list of small showers
This first of our showers is the Capricornids, which will peak on July 26, but will extend from July 10 to August 15. The radiant peaks in the south around 1:45 a.m. At most, only a few bright Capricornids will appear per hour, but this year these meteors will be handicapped by a bright gibbous moon shining in the east-southeast sky.
It will be just two days before the Australides Piscis reaches its maximum on July 28 (July 15 to August 30). The radiant will cross the meridian at 3:30 a.m. This is a smaller flow; only about eight members per hour will be visible to observers, mainly in the southern hemisphere, where the radiant rises high in the sky. But the light from a nearby last quarter moon will hamper visibility.
On July 28, the Delta Aquarids reach their peak (July 12 to August 23). This shower has two radiants, indicating that we are seeing two separate streams of celestial debris that produce faint and medium-speed meteors that burn up in Earth’s atmosphere. This shower produces up to two to three dozen meteors per hour, with the radiants peaking in the south around 3 a.m. But the same last quarter Moon that will interfere with the Australids Piscis will likely also reduce the number of Delta Aquarids that can be seen.
The Alpha Capricornids are another low-intensity meteor shower. They begin around July 3, peak on July 31, and end on August 15. The shower is at its brightest in the south around 1 a.m. Although few in number, the Alpha Capricornids frequently produce slow-moving, bright yellow meteors, sometimes fireball-like, with a long trail, that can be quite spectacular. The good news is that the moon has now shrunk to a thin crescent and will provide little, if any, information on the search for these meteors.
The last minor shower before the Perseids is the Iota Aquarids, another two-radiant shower with numbers detectable from July 15 to August 25. Peak activity occurs on August 6, with only about six members per hour observed under good conditions; the radiants reach their highest point in the south at 2:45 a.m.
After the Perseids, the last star shower of the summer is the Kappa Cygnids. The range for this shower is from August 3 to 28, with a peak on August 17. Although the maximum rate is only three per hour, the shower is classified as “slow-moving and sometimes bright with flaming fireballs,” and the careful observer can be well rewarded for their time. The hours before midnight are the best for this shower. The radiant is just north of the star Kappa Cygni and passes almost overhead at 10:30 p.m. Unfortunately, a nearly full moon will light up the sky most of the night.
A month of summer meteors
We include here radiant maps, courtesy of Yoshihiko Shigeno of the Nippon Meteor Society (NMS), plotted to facilitate understanding of the distribution of meteor visual radiants. Each map is divided into ten-day intervals—late July, early August, and mid-August—and each detected meteor radiant position is marked with a small “x.”
Note that in late July, the most active regions are in Capricorn, Aquarius, and Perseus. By mid-August, the meteor radiants have largely dispersed in Aquarius, while the Perseid radiant has become prominent.
SPACE.com will publish a complete viewer’s guide to the upcoming Perseid star shower in the night sky on August 9. Stay tuned!