Stargazers: Lyrids coming soon to pre-dawn sky
I had just begun one of my popular outdoor night sky presentations the other night when the audience erupted with gasps and cheers. I wanted to believe that it was my witty and captivating repartee that inspired their excited reaction, but I knew exactly what had happened.
They had seen a brilliant meteor exploding in the sky just over my shoulder. Of course, I immediately took credit for producing the spectacle as a dramatic opening to my show, but sadly, no one believed me.
It’s always remarkable to see how surprised people are when they spot a meteor, since bright meteors are not all that uncommon. In fact, on any clear, dark night, the average person can often spot three or four every hour — if far from city lights.
As dramatic as these falling or shooting stars might appear, most are random specks of interplanetary dust no larger than a sand grain that burn up in our atmosphere at heights of 50 miles or higher.
There are times of the year, however, when we can see more meteors than usual and are treated to what astronomers know as a meteor shower. These occur when the Earth encounters swarms of interplanetary dust particles, and we can see dozens falling every hour.
The most famous of all showers is the Perseid shower in mid-August. It’s quite a dramatic show, but I suspect it’s a favorite because it occurs during midsummer, when people are outdoors late at night.
No need to wait until August, though, because there’s a shower coming up next week: the Lyrid meteor shower. The Lyrids occurs when Earth slams into the dusty debris of Comet Thatcher.
Astronomers forecast that this year’s Lyrid shower should reach its peak in the hours before dawn on Sunday, April 22, but stargazers who are outdoors the night before may also see a few zipping across the sky.
If the sky is clear and you’re far from the blinding lights of a city, stargazers can expect to see as many as 20 meteors each hour.
These can appear everywhere in the sky, but you can easily determine whether one is part of the Lyrids swarm by tracing its path backward to its “radiant”; if it appears to come from the general direction of the constellation Lyra, it’s almost certainly part of the Lyrids swarm.
Meteors that appear to come from some other direction are what astronomers call sporadic meteors — random flecks of cosmic schmutz that just happen to collide with our planet.
Despite the Lyrids’ relatively low numbers, this shower can often produce bright, fast meteors, and about 15 percent leave behind persistent smoky trains that one can watch with binoculars for many minutes after the meteor itself has disintegrated.
On rare occasions, stargazers are treated to an impressive display of more than 50 Lyrids per hour, as they were in 1803, 1922 and 1982. Will this happen again in 2018?
Only time will tell.