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Perseid Shower Begins: Will There be an Outburst?
By Robert Roy Britt
Senior Science Writer
posted: 05:20 pm ET
08 August 2001
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Perseid Shower Begins: Will There be an Outburst All has been visually quiet under moonlit skies as the annual Perseid meteor shower inches toward its peak early Sunday morning, Aug. 12. | PRIME TIME | 
The part of Earth where dawn is breaking is always at the leading edge of our planet's plunge along its orbital path around the Sun. This part of the planet tends to "catch" oncoming meteors left by a comet, whereas the other side of Earth, where it is dusk or late evening, outruns the debris. For that reason, the hours between midnight and dawn are typically the best time to watch a meteor shower. More on the science of meteors and meteor showers | But things are picking up. Bright moonlight has blocked out all but the brightest meteors since late July. Before then, a normal nightly rate of Perseids -- about five per hour -- had been spotted, astronomers say. With the Moon waning and Perseid activity now picking up, each night beginning Thursday, Aug. 9, could prove rewarding for skywatchers. Early risers will have the best view. "On Friday morning I would expect that 10 Perseids could be seen in the last hour before dawn," said Robert Lunsford of the American Meteor Society. "This may increase to 15 on Saturday morning." The Perseids are expected to peak early Sunday morning, when rates might climb to as high as 50 per hour. Outburst? Could the rates go higher? Astronomers are not predicting an outburst, but the usually reliable Perseids have been known to surprise now and then. "In 1993, for example, the Perseids produced a wonderful and totally unexpected outburst, witnessed by hundreds of meteor observers around the world," said Lew Gramer, an amateur astronomer who runs "MeteorObs," a widely distributed e-mail newsletter devoted to meteor sightings. Some observers reported rates as high as 500 meteors per hour during a brief period in 1993. In other years, the count has soared above 200 per hour. "Could such an outburst occur this year?" Gramer wonders. "Well, we don't know. Which is one reason why it's fun to watch." The Perseids do not end after Sunday. They will wind down gradually through Aug. 22. Lunsford told SPACE.com that as many as 20 shooting stars per hour might be visible just before dawn Monday morning, Aug. 13. Evenings will prove less rewarding. Lunsford expects just 2-3 Perseids on Thursday evening, Aug. 9. The rate could increase to five per hour Friday and as many as 5-10 per hour Sunday evening. And each night from now through the end of the shower, a handful shooting stars not associated with the Perseids will streak across the sky. Of course, all meteor viewing depends on dark skies. City lights and even bright rural lights will reduce the number of meteors that are visible. Clouds and haze can also reduce the count.
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