The Perseids meteor shower is upon us again! Every year starting around July 23rd and lasting til August 20th, meteors can be seen periodically throughout the sky. This event has been happening at this time for over 2,000 years. So when you see a meteor zip across the sky, it's kind of like looking at history.
The meteor shower is associated with the comet Swift-Tuttle passing close to Earth. The meteors are actually debris that have broken off the comet and are just following it around until it gets close to Earth and gets pulled in. Fun fact, if the Swift-Tuttle perihelion passage (a sciencey way of saying orbit) is off by 15 days, it has a likely chance to strike Earth. It's impact would be 27 times stronger than the comet that killed the dinosaurs!
If it's part of a comet named Swift-Tuttle, than why is it called the Perseids?
Simply because of where it appears from! The meteors can be seem coming from inside of the constellation Perseus. Perseids derives from the greek term Perseides, which means sons of Perseus. So if you're outside seriously looking for the meteors, break out a star map and look for the Perseus constellation. If you have a smart phone or tablet, I highly recommend downloading Google Star Map. It's my personal best friend outside at night. If you've ever been interested in the stars, this will excite you to no end. I remember the days of having to fuss with paper star maps.
While the meteor shower happens for such a long period of time, it peaks on August 13th. So get your shooting star wishes ready and have a seat outside. Unfortunately sometimes the moon can kind of dampen those plans. In 2009 the meteor shower had it's highest zenithal hourly rate (more sciencey terms for meteors-per-hour) of 173, but a waning moon made some of the fainter ones hard to see.
Not this year though. The moon hits it's last quarter on August 9th and becomes a new moon on August 23rd. That is some pretty good moon positioning to see some meteors. Now all you have to do is keep the clouds out of the way.
In closing, another fun fact. If your catholic, your religion refers to these meteors as the "Tears of St. Lawrence" because he became a saint around that time. I understand why he'd be crying, he martyred himself and they cooked him on a grill. Thus making him the patron saint of cooks!