Astro Bob: Into every April a few Lyrids must fall
The annual meteor shower peaks in the early morning Friday, April 22, and Saturday, April 23.
Like April raindrops pelting the ground, bits and pieces of a comet will pepper Earth's atmosphere the next two mornings to produce the Lyrid meteor shower. This is annual event that occurs when the Earth passes through the debris trail shed by Comet Thatcher , which orbits the sun once about every 415 years.
Entering the atmosphere at around 103,000 mph (46 kilometers per second), the particles heat up and go poof! They're mostly the size of sand grains, but their rapid passage ionizes (excites) air molecules along the way, creating streaks of light called meteors. Most last less than a fraction of a second, but they make us ooh and aah.
From a dark sky the shower produces about 10-15 meteors per hour from a radiant located about 8 degrees southwest of brilliant Vega, the brightest star in the constellation Lyra the Lyre. That's where the Lyrids get their name even though the radiant — where the meteors stream from — is located in Hercules.
The shower has long been associated with Lyra because of Vega's prominence and sloppy constellation boundaries. When constellation borders were finally set in 1930, the Lyrid radiant ended up in neighboring Hercules.
This year, the shower peaks around 2 p.m. Central Standard Time on Friday, April 22, not exactly an optimum time for meteor-watching in the Americas. Thankfully, the meteor stream is fairly broad, with enough material to provide a reasonably good display on either side of maximum. Dress warmly and lay back in a lounge chair under a warm blanket. No other equipment is needed. These are your best viewing times:
Thursday night, April 21-Friday morning, April 22: 11 p.m. local time until moonrise (around 2:30 a.m. Friday)
Friday night, April 22-Saturday morning, April 23: 11 p.m. local time until moonrise (around 3:30 a.m. Saturday)
The later you stay up, the higher the radiant climbs, and the more meteors you'll see. Up to a point. Light from the last quarter moon, which rises around 3 a.m., will reduce the number by half. Whatever time you choose, give the shower at least an hour, and keep expectations low. You may only spot a few meteors, but knowledge of what you're seeing always helps deepen one's appreciation.
To confirm a Lyrid sighting, just trace the meteor's path backward. If it points toward Vega, it's a piece of Thatcher's Comet. Mr. A.E. Thatcher, the New York astronomer who found this trophy back in 1861, would be tickled to know you cared enough to stay up late — or get up early.
The Lyrids are known for occasional "outbursts" that recur in multiples of 12 years related to the gravitational influence of Jupiter. The last happened in 1982, when observers briefly recorded an hourly rate of 250 meteors. As you relax and enjoy the shower, know that it has a long history. People have been staying up late for the Lyrids for more than 2,700 years. Chinese astronomers first recorded the shower in 687 B.C.
Wishing you clear skies so you can be part of the timeline, too.
"Astro" Bob King is a freelance writer for the Duluth News Tribune.