Summer's shooting stars

Carnegie, Jul/Aug 2002 by Radzilowicz, John

It's time for the annual summer arrival of the Perseid Meteor Shower! These "shooting stars of August" generally put on the best performance of the year among meteor showers.

Meteors, or "shooting stars," are swift flashes of light that can dash across the sky on any night of the year. These flashes are not caused by stars, but by tiny sand grain-sized pieces of rock that collide with Earth's atmosphere. These pieces of space dust are moving at tens of thousands of miles per hour as they plunge into the air. At these speeds, they are quickly vaporized, creating a beautiful flash of light.

Occasionally, Earth encounters large amounts of this space debris, usually left behind by passing comets. At such times, the number of meteors seen can increase dramatically. We call these events meteor showers. Each August we plunge through the trail of material left behind by Comet Swift-Tuttle, and meteors seem to pour from the area of the sky that contains the constellation Perseus. The Perseid Meteor Shower has been known to deliver more than a meteor a minute under clear and dark skies.

Viewing the Perseids is simple. No special equipment is needed. You'll want to be able to see as much of the sky as you can, so open spaces and dark hilltops would be good locations for viewing. The meteors will seem to come from the northeastern sky where Perseus is located, but the meteors spread out over the sky and you may see them in any area.

Best viewing times are between midnight and dawn on the nights of August 11 and 12. Those times will let you see the peak of the shower, but it is also possible to see some of the meteors at earlier times of night and for nearly a week before and after the peak.