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.

This year’s Perseid peak lines up with the full moon, which will make it harder than usual to view some of the show.