CU-Boulder astrophysicist Doug Duncan says this year's annual Perseid meteor shower and its natural nighttime light show will be particularly good as the display becomes visible over Colorado Aug. 10-13.
"The moon will be nearly new, so it's an especially good time to see the meteor shower," said Duncan, director of Fiske Planetarium and Sommers-Bausch Observatory.
"A dark sky makes a big difference. If you're watching from Denver, you might see a couple of meteors per hour. From the suburbs you might see five to 10 per hour. In the mountains, where the sky is really dark, you could see 50 or more per hour," Duncan said. The peak of the shower will come during the early morning hours of Aug. 12.
Meteor showers occur when the Earth crosses the path of a comet, sweeping through debris left behind along the orbit. Millions of chunks of ice and dust make up the tail of a comet. These chunks are remarkably small – most are the size of a grain of rice or smaller -- and travel through the solar system at more than 36,000 miles per hour.
The Perseid meteor shower is caused by the Earth passing through the tail of Comet Swift-Tuttle, which is in orbit around the sun. The chunks of space junk that make up the tail are only seen as meteors when they get caught in Earth's gravity and burn up in the atmosphere. The Perseid meteor shower is named for the Perseus constellation from which the meteors, or shooting stars, appear to radiate.
Considerably more Perseid meteors will be visible after midnight each night during the peak dates. Duncan, who spent four years as a science commentator for National Public Radio station WBEZ in Chicago, used an analogy to explain why there aren't as many meteors before midnight.
"Think of the meteors as bugs and the sky as the windshield of a car. After midnight, our night sky will be facing 'forward,' in the same direction as the Earth orbits around the sun. As a result, after midnight we see a lot more 'bugs' hitting our 'windshield.' "
Duncan encourages people to camp out to see the Perseid meteor shower and to stay up late for optimum viewing. While the best shower will come in the early morning of Aug. 12, there will be half to two-thirds as many meteors visible during the early morning of Aug. 11 and Aug. 13.