This would be an excellent week to watch the Lyrid meteor shower, except for a pesky moon that will wash out much of the show, astronomers say.
The annual Lyrid meteor shower peaks this year on the morning of Earth Day, April 22, but will be visible for much of the week.
However, the presence of a more than half-full moon in the sky — what astronomers term a 'waning gibbous' moon — will make watching for the falling stars less a thrill than in some years.
Still, "the Lyrids are bright, so they can withstand some moonlight, said Deborah Byrd, editor of the astronomy and science website EarthSky.org.
The showers' peak will hit just before dawn Tuesday.
In some years, the Lyrids produce as many as 20 meteors per hour at their peak. There's "no way we'll be seeing that many this year. Still, even one bright meteor streaking along in a moonlit sky can be beautiful," Byrd says.
The moon "will spoil a lot of the show. So I would not set high expectations," says Bill Cooke, who directs NASA's Meteoroid Environment Office at Marshall Space Flight Center in Huntsville, Ala.
Weather permitting, NASA will host a live video stream from one of its meteor cameras on Tuesday.
The best bet for those who want to catch a glimpse of these yearly visitors is to choose viewing hours carefully.
"People have two choices this year when watching the Lyrids. They can try to watch before moonrise, in late evening on April 21, or they can try to watch in the hours before dawn on April 22, when the moon will be in the sky," Byrd says.
To check moonrise and set times in your area, www.sunrisesunset.com offers customized calendars for specific locations.
The meteor shower gets its name because it appears to radiate from a point just to the right of the blue-white star Vega, which is the brightest light in the constellation Lyra the Harp.
The Lyrids are one of the oldest known meteor showers. The Chronicle of Zuo, written in China in 687 BC by Qiuming Zuo, records that, "at midnight, stars fell down like rain."
With the Lyrids falling on Earth Day, it's a nice day to remember that our planet is made of the same star stuff as meteors, says Ron Hipschman, a scientist at the Exploratorium, an interactive science museum in San Francisco.
The ground we stand on is simply a larger piece of that same material, he says.
In San Francisco "people used to 'pet' the meteorite on display at the California Academy of Sciences and be amazed that this 'came from space,'" he said.
What they didn't realize, he says, was that they, too, were standing on a similar rock in space!"