They return year after year, and for many of us, they spell holidays and warm summer nights. But who — or what — are they? The Perseid meteors, of course!
Each year around mid-August, Earth passes close to the orbit of periodic comet 109P/Swift-Tuttle, whose wake is peppered with billions of dust particles that give rise to the famous Perseid meteor shower. However, the quality of the celestial show varies dramatically from year to year, mainly as a function of Earth’s distance from the densest parts of the particle stream, but also as a function of the Moon’s presence.
The Perseids in 2022
Unfortunately, the Perseids will take place under the worst possible conditions in 2022. Peak activity is expected around 9 p.m. (Eastern) on August 12; the full moon set to occur on August 11 will be the limiting factor for viewing the shooting stars. The nights closest to the shower’s peak (August 12-13, and also 11-12), when the meteors should be most abundant, will be affected by the encroaching light from our natural satellite.
Indeed, the presence of a bright Moon creates a form of “natural” light pollution that’s impossible to escape from, event in remote locations away from city lights. This veil of light overpowers the faintest shooting stars; only the occasional bright meteor can peek through such conditions, thereby decreasing the total number that can be seen. And for a few days around full moon, the Moon is visible from dusk to dawn, giving us nearly no break at all.
During the two nights closest to peak activity, one can expect to count no more than 3 or 4 Perseids per hour, and even so, only under very clear skies with an unobstructed, 360-degree point of view. Tips for die-hard observers: keep the glaring Moon behind you, hidden behind trees, a hillside or some other obstruction, and concentrate your attention toward the northern part of the sky.
On a positive note, keep in mind that the Perseids are active (though at much lower rates) from the end of July through the third week of August. Even if the number of potential meteors drops by half for each 24-hour period that separates us from the time of peak activity, you’ll probably get a chance to spot a few shooting stars under the dark, moonless skies of early August—provided you get away from light polluted cities. In fact, until August 5, the Moon sets before midnight, leaving dark skies during the second half of the night until dawn—which is perfect, since the radiant of the shower climbs higher in the sky during the later hours of the night, thus increasing the number of potential meteors. Is your wish list ready?
The outlook for 2023 is much better: as the Perseids reach their maximum, the Moon will be just a thin waning crescent and won’t spoil the view.