The Perseid meteor shower takes place each year as Earth travels through the debris shed by comet 109P/Swift-Tuttle.

Meteor showers occur when Earth passes through trails of dust and debris left behind by comets or asteroids. The Perseids come from a comet called Swift–Tuttle, which orbits the Sun once every 133 years. The comet's dust particles enter Earth's atmosphere at speeds of about 37 miles (59 kilometres) per second.