Anyone who stares into the summer night sky for even a short time is likely to notice a few “shooting stars” darting across the sky.
The best meteor display of the summer comes in the second week of August during the annual Perseid meteor shower, which at its peak around the night of August 11 and 12 is capable of producing 50 to 100 fast, bright meteors per hour for a single hour observer. Many blazing meteors with trains are visible in good skies. 2024 will be a very good observing year for the Perseids because the bright moonlight will not interfere.
The first precursors of the Perseid stream began to appear around July 25. At best, you’ll only see a few per hour, but the numbers will start to increase in the second week of August. The last trailing Perseids can still be seen as late as August 18.
In general, Earth experiences richer meteor activity during the second half of the year. And you’re more likely to see twice as many meteors per hour in the predawn hours compared to the evening hours. This is due to the fact that in the hours before midnight we are on the “back” side of the Earth, due to our orbital motion in space.
So any meteor particle would normally have to have an orbital velocity greater than Earth’s to “catch” us. However, after midnight, when we are facing the “leading” side of the Earth, any particle that lies in the planet’s orbital path will enter the Earth’s atmosphere as a meteor. As such objects collide with our atmosphere at speeds of 7 to 45 miles (11 to 72 km) per second, their energy of motion is rapidly dissipated in the form of heat, light, and ionization, creating short-lived streaks of light popularly referred to as ” falling 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 equipment, consider our best astrophotography cameras and best astrophotography lenses.
Meteor superstates
Along with the Perseids, however, there are many other minor meteor shows that are active at different times in July and August. While the hourly rates from these other meteor showers are only a fraction of the numbers produced by the Perseids combined, they provide a wide variety of meteors of different colors, speeds, and trajectories. Summer meteors, which occasionally fly across the line of sight, are especially noticeable between late July and the third week of August.
And between July 26 and August 21, there are no less than six different secondary displays that are active. These include Capricornids, Delta Aquarids, Piscis Australids, Alpha Capricornids, Iota Aquarids and Kappa Cygnids.
The radiant points for five of these showers are at their highest, about midway up in the southern sky between 1 and 3:30 a.m. local daylight time. The radiant is the place in the sky where the paths of the members of the soul, if extended back, will cross near the star or constellation for which the soul is named. Many people are fooled into thinking that this is the best place to look for these meteors, but in fact the greatest number will be seen in the area of the sky overhead and to the south.
In addition to the shower meteors, there are always sporadic, apparently unrelated ones that appear at an average rate of about seven per hour. The duration of the rain in days is somewhat arbitrary, as the beginning and end are gradual and indefinite.
The only equipment you need is your eyes and a little patience.
As one longtime meteor enthusiast noted, “Meteor watching is relaxing and enjoyable, potentially dramatic and just plain fun!”
The little shower list
This first of our rains is Capricornus, which peaks on July 26th, although it extends from July 10th to August 15th. The radiant reaches its highest point in the south around 1:45 a.m. At most, only a few bright Capricornus will appear per hour, but this year those meteors will be thwarted by a bright moon shining brightly in the east-southeast sky.
Only two days will pass until the Piscis Australids reach their maximum on July 28 (July 15 – August 30). The radiant crosses the meridian at 3:30 am. It is a smaller stream; only about eight members per hour will be visible to observers mostly in the southern hemisphere, where the radiant climbs high in the sky. But the light from the nearby last quarter moon will hinder visibility.
In addition, on July 28 comes the peak of the Delta Aquarids (July 12 – August 23). This stream has two radiants, indicating that we are seeing two different streams of celestial debris that produce weak, medium-velocity meteors burning up in Earth’s atmosphere. At most two or three dozen meteors per hour are produced by this shower, and the radiants reach their highest point in the south about 3 o’clock in the morning. But the same last quarter moon that will interfere with the Piscis Australids is also likely to reduce the number of Delta Aquarids that can be seen.
Another light rain is Alpha Capricornus, which begins around July 3rd, peaks on July 31st, and ends on August 15th. Radiant is highest in the south around 1 am. Although they are few in number, Alpha Capricorns often produce slow, bright…sometimes, a class of fireballs—yellow meteors with long trails that can be quite spectacular. Good news: the moon has now waned to a thin crescent and will provide little, if any, conclusion to the search for these meteors.
The last minor shower before the Perseids is the Iota Aquarids, another biradial stream with detectable numbers from July 15 to August 25. Peak activity is on August 6, with only about six members per hour observed in good conditions; radiants reach their highest point in the south at 2:45 am
After the Perseids, the last summer shower is the Kappa Cygnids. The boundaries of this rain are from August 3 to August 28, with a peak on August 17. Although the maximum speed is only three per hour, the flow is classified as “slow moving and sometimes glittering with flaming fireballs” and the careful observer can be well rewarded for the time spent. The hours before midnight are the ones you should choose for this shower. The radiant is just north of the star Kappa Cygni and passes almost overhead at 10:30 p.m. Unfortunately, the nearly full moon will illuminate the sky most of the night.
A month of summer meteors
Here we include radiant diagrams courtesy of Yoshihiko Shigeno of the Nippon Meteor Society (NMS), drawn to make the distribution of visual meteor radiants easier to understand. 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 at the end of July the most active regions are in Capricorn, Aquarius and Perseus. By mid-August, the meteor radiants became widely scattered throughout Aquarius, while the Perseid radiant became dominant.
SPACE.com will publish a comprehensive viewer’s guide to the upcoming Perseid shower in the night sky on August 9. Stay on the line!
