Sky watch: The Leonid meteor shower

Anyone who has ever gazed into the night sky for more than just a few minutes has almost certainly seen a burst of light appearing out of nowhere and disappearing just as quickly.

We call such startling phenomena romantic names such as "falling stars" or "shooting stars," but a more accurate term is "meteors."

These are often tiny particles from space (meteoroids) that slam into our upper atmosphere at tens of thousands of miles per hour andglow brilliantly as they meet their fiery demise (meteors). Believe it or not, most are barely the size of a grain of sand.

If a walnut-sized meteoroid should encounter our atmosphere, it would outshine everything in the sky and even cast a shadow. These fireballs can fragment, explode or leave lingering trails behind them. And if a celestial body is large enough to survive its plunge through our atmosphere and crash to Earth, it would then gain a new name: a meteorite.

At times throughout the year, our planet encounters swarms of meteoroids left behind by ancient comets, and we experience a meteor shower. While we name these for the constellation from which its meteors appear to radiate, we can see meteor showers all around the sky.

This coming week, we will experience one of the more interesting showers and, because it appears to originate among the constellation Leo (low in the east after midnight), we know this display as the Leonid meteor shower.

The Leonids are best known for their 33-year peaks, when sky watchers report seeing hundreds -- or even thousands -- per hour. We expect nothing like this in 2011, of course, but Leonids are fascinating to watch. The 15 or 20 meteors that rip through our atmosphere every hour are very fast; they can burst brightly in blue or green and often leave a beautiful trail of smoky material behind.

As luck would have it, light from the last quarter moon will reduce the number and brightness of Leonids we see this year, but by facing away from the moon, we hope to see quite a nice display. Scientists figure this year's Leonid shower should peak around 11 p.m. on Nov. 17. While Leo will lie well below the horizon at that time, we may actually see a few meteors on the night of Nov. 17. Our best bet, however, will come after midnight and before dawn on the morning of Nov. 18.

The trick is to get far away from city lights, dress warmly, lie on a sleeping bag or lawn chair and scan the entire sky with your eyes.

You need no equipment, but when one of the great Leonid fireballs bursts across the heavens and leaves behind a lingering trail, you can use binoculars to watch it as it twists and turns for several minutes in upper atmospheric air currents.

Visit AstronomyLive.com to learn more by clicking on "Event Calendar" and reading about the Leonids Meteor Shower.