Strong Leonid Meteor Shower Predicted for 2009
Credit: Lorenzo Lovato

Editor's Note: See our new 2009 Leonids Meteor Shower Viewer's Guide. The story below was published in 2008.

The annual Leonid meteor shower put on some dramatic sky shows in 1999 and 2001, but in recent years the event has been comparatively mundane.

Next year could be another doozie.

Astronomers now predict the 2009 Leonids could produce more than 500 shooting stars per hour for skywatchers with clear skies in certain locations. Asia looks to have the best seats, but North America might not be left out.

Such a rate would be much less than the brilliant displays a few years back, but still delightful to watch.

"On Nov. 17, 2009, we expect the Leonids to produce upwards of 500 meteors per hour," said Bill Cooke of the NASA Marshall Space Flight Center. "That's a very strong display."

Astronomers from Caltech and NASA base their joint prediction on an outburst that occurred this year, on Nov. 17, that they figure heralds even more intense activity next November.

The Leonids are created by bits of debris left behind by the repeat passages through the inner solar system of comet 55P/Tempel-Tuttle. There are several streams. This year, Earth passed through one laid down in the year 1466. Most astronomers did not expect it to produce much.

But observers in Asia and Europe counted as many as 100 meteors per hour, according to a NASA statement today. That shows the 1466 stream is rich in meteor-producing debris. And in 2009, our planet will pass through this stream again, but this time closer to its center, where more material should be there to slam into our atmosphere.

The stuff, typically the size of a sand grain, vaporizes in the atmosphere. Some pea-sized objects create dramatic fireballs.

When showers exceed 1,000 meteors per hour, they are called storms. This one is not expected to reach that level.

The timing: "We predict a sub-storm level outburst on Nov. 17, 2009, peaking sometime between 21:34 and 21:44 UT," Cooke said. That favors observers in Asia, although Cooke won't rule out a nice show over North America when darkness falls hours after the peak. "I hope so," he said. "It's a long way to Mongolia."