LOS ANGELES, CA (Catholic Online) - The shower is caused as the Earth enters a debris field left over from the Comet Swift-Tuttle that occurred in 1862.

If you live in rural, isolated areas far beyond the glow of modern American cityscapes, you will have a very good chance of seeing the shooting stars as they crest across the evening sky. If you live on a mountaintop, there's a good chance you'll be able to see as many as 108 meteors an hour.

The best viewing locations will be in the Northern Hemisphere, with Southern Hemisphere sky-watchers limited to perhaps 30 or 40 events an hour at the shower's peak.

Of the more than 364 meteor showers listed by the International Astronomical Union, the Perseids turn in the best show of the lot. This year's Perseid show is poised to be above average.

Amateur astronomers can thank the 109P/Swift-Tuttle, the comet whose debris is responsible for the show. It swings around the sun once every 135 years, spewing dust and gas as it nears the sun and heats up. The comet's last pass was in 1992.

Earth began moving into Swift-Tuttle's stream of dust in July. The debris "is a very old stream that has been building for a long time and is a very dense concentration of dust," Peter Jenniskens, a meteor researcher at the SETI Institute says.

Indeed, "if you look back at records from the Middle Ages, you can see that people in the Middle Ages were seeing the Perseid meteor shower," he says.

This year's display is unlikely to match last year's, when the shower had three peaks - one of which topped 200 meteors an hour. The 2010 event benefits from two conditions that promise to keep the display above average.

First, it's happening during a new moon, which means faint meteors will not have to compete with moonlight for your attention. Second, Earth will be passing through a denser patch of Swift-Tuttle's dust stream than usual.

The meteors will appear as though they are emerging from a patch of the sky containing the constellation Perseus. That constellation is high enough in the night sky by midnight Thursday.