April Showers: Lyrid Meteors Peak on the 22nd

By: The Editors of Sky & Telescope April 18, 2006 0

April 18, 2006

Contacts:
Alan M. MacRobert, Senior Editor
855-638-5388 x151, [email protected]
Marcy L. McCreary, VP Marketing & Business Dev.
855-638-5388 x143, [email protected]

Note to Editors/Producers: This release is accompanied by a broadcast-quality animation; see details below.

The annual Lyrid meteor shower should reach its peak activity late Friday night and early Saturday morning, April 21–22, 2006. The Moon, a thick waning crescent, doesn't rise till about an hour before morning twilight begins, so it will hardly interfere with the shower at all this year. Still, the Lyrids are generally weak. Even at their maximum only 10 to 20 "shooting stars" per hour may appear.

But there have been some remarkable exceptions. In 1982 the rate unexpectedly reached 90 for a single hour, and 180 to 300 for a few minutes. A brief outburst of 100 meteors per hour was also seen in 1922. And on April 20, 1803, the residents of Richmond, Virginia, upon being rousted out of bed by a fire bell, were startled to see great numbers of meteors in all parts of the sky.

The time to watch will be late Friday night, April 21st, until the first light of dawn on Saturday morning the 22nd. You'll need no equipment but your eyes. Find a spot with an open view of the sky and no bright lights nearby. Bring a reclining lawn chair, bundle up warmly, and bring a sleeping bag; clear nights can get very cold, even in springtime.

"Arrange the chair so that any bright lights are behind you out of sight, lie back, and watch the stars," says Sky & Telescope senior editor Alan MacRobert. "Be patient."

If you trace each meteor's direction of flight backward far enough across the sky, you'll find that the imaginary line you're drawing crosses a spot between the bright summer star Vega and the keystone pattern of the constellation Hercules. This spot is the shower's radiant, the perspective point from which all the Lyrids would appear to come if you could see them approaching from the far distance. The radiant is low in the east-northeast by 11 p.m., higher up in the east by 2 a.m., and overhead by the first light of dawn. But you don't have to look there. Just watch whatever part of your sky offers the darkest view.

Generally, there will be more meteors than usual visible for a few nights on either side of the peak of a meteor shower.

The Lyrid meteoroids (particles) are tiny, sand-grain- to pea-size bits of icy debris shed from Comet Thatcher, discovered in 1861. Over the centuries these bits have spread all along the comet's orbit to form a sparse, moving "river of rubble" hundreds of millions of miles long. Earth's own annual orbit around the Sun carries us through this stream of particles every mid-April.

The particles are traveling 30 miles per second with respect to Earth at the place in space where we encounter them. So when one of them strikes Earth's upper atmosphere (about 50 to 80 miles up), air friction vaporizes it in a quick, white-hot streak.

More information on meteor showers and how to watch them is available online at SkyandTelescope.com in Observing > Celestial Objects > Meteors.

Sky & Telescope is pleased to make the following animation available to our colleagues in the news media. Permission is granted for one-time, nonexclusive use in print and broadcast media, as long as appropriate credit (as noted in the caption) is included. Web publication must include a link to SkyandTelescope.com.

These are reduced-size frames from Sky & Telescope‘s broadcast-quality QuickTime animation showing how a meteor is formed when a speck of debris burns up in Earth’s upper atmosphere.

Sky & Telescope animation by Steven A. Simpson.

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