A trick to catch Perseid meteor shower 2011 in spite of a full moon

One of the best meteor showers of the year, the Perseid meteor shower, peaks Friday night.

While light from a nearly full moon will likely reduce the number of "shooting stars" you might see, head out after midnight to watch anyway.

And bring along your FM radio. What you can't see, you just might be able to hear, as beyond-the-horizon FM radio signals bounce off the streaks of hot, ionized gas the meteors leave in their wakes. Some of those signals come as a single ping. Others last long enough to pick out a snippet of a song or a station ID.

The Perseid shower is one of the most widely viewed meteor showers of the year. The meteors are bits of debris that comet 109P/Swift-Tuttle casts off when it approaches the sun, warms, and begins shedding its dust and gas. The shower gets its name from the constellation Perseus, which appears to be the point in the sky from which the shower originates.

Swift-Tuttle returns once every 130 years. But each August, Earth's orbit takes it through the debris cloud Swift-Tuttle leaves behind. Over the last five years, the number of meteors one could expect to see in an hour under dark skies has ranged from 93 in 2007 to 173 in 2009. But, like this year, 2009's display was tempered by a nearly full moon.

And that's where an FM radio might help bridge the gap. The approach works best with an FM radio with a digital display.

The trick is to first find a dead frequency on the FM band (make sure the frequency is dead because there is no nearby station broadcasting on it, not because you merely have the antenna pointed in the wrong direction or not fully extended).

When a signal bounces off a meteor trail, you should hear a ping, something like this.

It might be best to wear headphones.

Some people find a dead spot on the FM band and then look for a particular FM station that broadcasts on that frequency but is too far away to be heard normally.

One source for listings is OfficialUSA.com.

As simple as detecting meteors on an FM radio sounds, sophisticated versions of this technique are used by amateur astronomers to tally the intensity of meteor showers and report the results to the International Meteor Organization, which keeps exhaustive records of meteor activity.

One downside, of course, is that the meteor you hear may in fact come from another source than Swift-Tuttle and so may no be part of the Perseid shower. Visually, you can draw an imaginary line along a meteor's streak to its "radiant," or point of origin. Radio? Not so much.

But if you catch that snippet of Elvis or Green Day, you've come about as close as you'll ever get to the music of the spheres.