Meteor showers occur when Earth passes into a region of comet debris. The debris (rock and dust the size of grains of sand) burns when it collides with our atmosphere. Meteor showers are named after the radiant, or constellation where meteors appear to originate.
Meteors in the Perseid meteor shower appear to originate from the constellation Perseus, but the debris is left behind by the comet 109P/Swift-Tuttle, which orbits the sun every 133 years.
The Perseid meteor shower occurs each year from late July until late August. This year the peak days are August 11-13.
Viewing Tips
The most important tip to viewing a meteor shower is to choose a location where the sky is dark and there is a wide open view of the sky. Avoid city light pollution by going to a park or public sports field. Be mindful of park hours– many parks close at dusk.
You do not need a telescope or binoculars to view the meteor shower. These actually make it more difficult to see the show because a telescope or binoculars can only magnify a small region of the sky. The meteors will cross the entire sky, so you want to be able to see as much as possible.
You do not need to look at any part of the sky, but they do appear to come from near the constellations of Cassiopeia and Perseus in the northeast.
Before going outside, look up the weather and when the moon rises in your location. It is important to look at the weather as clouds and rain will prevent you from seeing the meteors. Also, the moon will wash out many dimmer meteors so you may want to choose a time before the moon rises.
For example, the moon rises at 12:14 am on Wednesday morning in Philadelphia so a good time to look for meteors would be 11 pm Tuesday night, before the moon rises. (To look up when the moon rises in your location, you can use https://www.timeanddate.com/moon/usa/).
Plan to be outside for at least an hour. If you have a lawn chair, lean back in it. Else you can lie on the ground or on top of a blanket. You might want to grab pillows, blankets, a jacket and a snack to enjoy.
Let your eyes adjust to the low lighting for 20-30 minutes. During this time, you will want to refrain from looking at bright lights– even your phone.
Once your eyes adjust, fix your gaze about halfway up the sky; more activity is visible at lower elevations. Expect to see 15-20 meteors per hour when the moon is visible, and more if it is below the horizon.
NASA reports that the best time to view the Perseid meteor shower is between local midnight and sunrise.
Miss the meteor show? Don’t worry. It will return next August and there are other shows to look forward to, such as the Geminids in December.
Happy observing 🙂