Strong Leonid Meteor Shower Expected Nov. 17

Circle Nov. 17 on your calendar, for early that morning a moderate to possibly very strong showing of annual Leonid meteor shower is likely.

The very strong display will favor those living across most of central and eastern Asia. In this region, meteor rates might briefly rise to a few hundred per hour (the time frame for the most intense activity is anticipated sometime around 21:40 GMT).

A far more modest, but still potentially enjoyable display of a few dozen Leonid meteors per hour is expected to favor North America. In the United States and Canada, eastern observers will be particularly well-positioned for maximum activity, expected sometime between 3:30 and 5:30 a.m. EST, when the radiant of the Leonid shower will be well up in the dark southeastern sky.

A meteor shower's radiant is the perspective point from which all the meteors would appear to originate if their paths were traced backward far enough. The higher the radiant is, the more meteors flash into view all over the sky (though meteors can appear anywhere in the sky, so focusing on the radiant is not necessary).

The Leonid radiant is within the so-called "Sickle" of Leo; a backwards question-mark pattern of stars that outlines the head and mane of the constellation Leo, the Lion. Hence the meteors are known as "Leonids."

Not in the East? Don't fret. Observers all across North America may experience a good Leonid show with "shooting stars" streaking across the sky every few minutes.

Also a big plus in 2009 is the lack of any interference from the moon. New moon is on Nov. 16, so skies will be dark for catching the fainter meteor streaks. And the first light of dawn will not break until shortly after 5 a.m. local time.

Europe and Africa appear largely out of luck. This year's first round of expected enhanced activity will happen chiefly during their daylight hours. ...

As the Earth encounters the debris left behind by the comet's previous passes through our orbit, these tiny fragments of the comet – typically no bigger than a sand grain or the occasional pea – impact our atmosphere at speeds of up to 45 miles per second (71 kps), causing them to blaze briefly but brightly in the night sky.

via Strong Leonid Meteor Shower Expected Nov. 17 - Yahoo! News.