This year the Perseid Meteor Shower is best viewed late at night but before midnight on Tuesday night, August 11, 2020. Look toward the east and you should occasionally see a meteor trail in the sky. The rate is expected to be about 50 meteors per hour, but it could be a bit higher. This is a slowly unfolding event that takes patient observing, but you may be rewarded with a bright streak in the sky as a small pebble hits the earth’s atmosphere and burns up.
Just like driving through a snowstorm, the earth’s orbit intersects the debris of comet Swift-Tuttle, a comet with a 133-year orbit traveling through our solar system. The debris is littered throughout the entire orbit, so every year around August 11 the earth goes through the cometary debris of pin-sized grains and small pea-sized pebbles. As the debris hits the earth’s atmosphere, the friction of the air heats and vaporizes the pebbles, resulting in a glowing streak across the sky.
The streaks, known as meteor trails, appear to come from the constellation of Perseus (technically the “radiant point,” the direction of the stream of debris material hitting the earth). At midnight, the constellation of Perseus has just risen above the northeast horizon, but the meteor trails themselves may appear anywhere in the sky. Most will appear in the eastern sky.
The usual advice is to watch meteor showers after midnight, giving a better view from the earth’s “front windshield” as it orbits the sun and intersects with the comet debris orbit. But this year there is competition in the sky.
After midnight, as August 12 begins, the last quarter moon rises in the northeast at 12:23 a.m. in the latitude of the Washington, DC area. The fainter Perseid meteor trails will be washed out by the moon’s light.
All things considered, the best time this year to see the Perseid Meteors is August 11 between 11 p.m. and before moonrise at 12:23 a.m. Of course, there will be meteors before and after these times, but the apparent rate of meteors will be less than during the best observing time.
This article is reprinted with permission from the Analemma Society website.