for National Geographic News
The Perseid meteor shower will have to fight it out with a bright moon for visibility this year, but astronomers are still predicting a dazzling show.
From any vantage point in the world, you might see more than 80 meteors an hour streak across the sky during the best viewing time, when the moon's glare will be weakest—late Tuesday night and into the wee hours of Wednesday, local cloud and lighting conditions permitting.
The highest concentration of Perseid meteors hitting Earth's atmosphere will occur during Wednesday afternoon, when they'll be largely invisible.
The Perseid sky show is "always the best annual meteor shower," said Bill Cooke, the lead for NASA's Meteoroid Environments Office in Alabama.
"Visually, the best are the Geminids. But December nights are cold, and people don't want to freeze their rears off."
Perseid Meteor Shower Viewing Tips
The moon will provide some interference for the Perseids, at just over half full and rising around midnight. The best advice: Look away from the moon—and all other lights—so your eyes stay as dark-adapted as possible.
To see the Perseid meteor shower, bring a blanket to a place away from city lights and lie on your back, taking in as much of the sky as possible.
The Perseid meteors will appear to originate in the northeastern sky, near the constellation Perseus, and to shoot off in all directions, said Brian Skiff, an astronomer at Lowell Observatory in Flagstaff (see animated star chart below).
"Since the radiant point is close to ... Perseus, it is common to see them streaking right along the Milky Way, even as far away as Sagittarius," he said. "After midnight, Perseus will have risen higher in the sky, and the meteors can be seen in just about any direction."
Perseids: More Than a "Geek Pickup Line"
The Perseid meteors are bits of 2,000-year-old debris left behind by the periodic comet Swift-Tuttle. Earth's atmosphere collides with the debris at more than 38 kilometers (23 miles) a second (comet facts).
(Related: "Comet Swarm Delivered Earth's Oceans?")
The meteors generally get incinerated before they can strike the ground, creating the streaks of superheated, glowing air we call shooting stars.
NASA's Cooke has made a career of studying meteors, but that wasn't always his primary reason for watching meteor showers, he said.
"It was the best way to get the girls out on a date," he said. "It was used as a geek pickup line back in my day."
SOURCES AND RELATED WEB SITES