Sky Watch: Lyrid meteor showers
With springtime well under way, stargazers are beginning to retreat from the blinding lights of large cities to enjoy the sky in its true splendor. And what a great time to begin searching for "falling" or "shooting" stars, known to astronomers as "meteors."
Next weekend features the Lyrid shower; it reaches its best before dawn on Sunday, April 22, but stargazers might just catch sight of a few meteors flashing across the heavens the night before.
The Lyrid shower occurs when Earth slams into the dusty debris expelled by the ancient Comet Thatcher. And most are specks no larger than a sand grain that plummet into our atmosphere and disintegrate at heights of 50 miles or higher.
Next weekend, if the sky is clear and dark, you may spot as many as 20 meteors falling each hour before dawn. These can appear all over the sky, but you can tell if one is part of the Lyrid swarm by tracing its path backward; if it appears to come from the direction of the constellation Lyra -- not far from the bright star Vega in the northeastern sky -- it's almost certainly part of the Lyrid swarm. Otherwise, it's what astronomers call a "sporadic" meteor -- a random fleck of cosmic dust that just happens to collide with our planet while we watch.
Despite the Lyrids' relatively small numbers, this shower can surprise. On occasion, stargazers are treated to an impressive display of more than 50 per hour, as they were in 1803, 1922 and 1982. Will this happen again in next weekend's moonless sky?
There's only one way to find out!