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This picture shows a bright Leonid meteor that was seen in November 1998. The light from this meteor lit up some clouds, creating this beautiful photo opportunity!
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Courtesy of Lorenzo Lovato of Imola, Italy

Leonid Meteor Shower

The Leonid meteor shower is one of several major meteor showers that occur on roughly the same date each year. The Leonids typically "peak" (are at their greatest level of activity) in mid to late November. The Leonid shower's name is derived from the fact that its meteors appear to fan out from a point in sky, called the shower's "radiant", which lies within the constellation Leo.

In 2009, the Leonid shower is expected to peak on the night of Tuesday, November 17th. Since there will be a New Moon around this time, this year should be a good year to spot some Leonids. A bright Moon makes it hard to see meteors.

As is the case with most meteor showers, it will be possible to see Leonid meteors for several days before and after the peak on the 17th. In fact, it is sometimes possible to see some Leonids as early as November 14th and to continue to spot a few up to November 21st. At this shower's peak observers may be able to see as many as 100 "shooting stars" per hour under dark skies (away from city lights). However, the Leonids, as compared to other meteor showers, present a highly variable celestial show. The number of meteors visible at the shower's peak can change quite a bit from year to year in an unpredictable fashion.

The Leonids are actually bits of dust that have been shed over the centuries by a comet named comet 55P/Tempel-Tuttle! The dust, which spews forth from the comet's nucleus each time it passes near the Sun, gradually spreads out over the entire orbit of the comet. If Earth's orbit happens to cross the comet's orbit, the swarm of debris scattered along the comet's orbit is visible to us as a meteor shower. Since the Earth crosses the comet's orbit at the same time each year, each meteor shower is predictably visible at the same time of year, year after year.

Most meteors in a shower are quite small, about the size of a grain of sand. Leonids are among the fastest-moving meteors. These meteors typically strike our atmosphere while traveling at speeds around 72 kilometers per second (about 161,000 mph). Because of their high speeds, Leonids typically leave long, glowing trails in the sky.

Last modified October 20, 2009 by Randy Russell.

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