The coming weekend offers the best opportunity since the start of the year to watch a display of shooting stars as the Lyrid meteor shower reaches its peak.
Conditions will be favourable for 2017’s display as far as the Moon is concerned. It will be a waning crescent, rising a couple of hours before the Sun on Saturday morning, 22 April.
This means that moonlight will not interfere to drown out the fainter meteors for most of the night, so if the sky is clear, it will be worth watching out for them. You could even try to catch some meteors with your camera.
Don’t expect too much, and ignore the news sites that promise a spectacular show. The peak rate for the shower under ideal conditions is usually no more than 15 – 20 per hour. Typically they appear to travel at medium to swift speed.
However, if you wrap up warm and sit comfortably in a deck chair or lounger, away from street lights, you could be rewarded with the sight of a few of these fleeting specks of space dust as they enter the atmosphere and become natural fireworks. Maximum is due at 11.00 UT.
The radiant of the shower lies not far from the bright star Vega in the constellation of Lyra, which gives the shower its name, though the radiant is actually just within the neighbouring constellation of Hercules. You can see the meteors in any part of the sky, but if you trace their paths backwards, you will find they intersect with the radiant because that is the direction from which they stream in from space.
Meteor showers are still not entirely predictable as far as rates are concerned, though astronomers are beginning to map more precisely the streams of dust that cause them. There have been years when the Lyrids showed enhanced activity with brief bursts when rates can become several times higher. The most recent occasion this happened was in 1982.
The Lyrids are produced by the dust shed by a comet that was last seen in 1861. Comet Thatcher, named after its discoverer Albert E. Thatcher is a long period comet, so-called because it takes more than 200 years to make one orbit of the Sun. Comet Thatcher actually takes 415.5 years to make one circuit, travelling out beyond Neptune.
The comet’s full catalog title is C/1861 G1 Thatcher. Its discoverer, Professor Thatcher, was an amateur astronomer in New York who found several comets. He spotted this one on 5 April, 1861, at magnitude 7.5. Within a month, it had become a bright naked-eye object with a tail.
Though we won’t see the comet again until the year 2276, the Lyrids are a regular sample of it delivered to our skies. In fact the shower is one of the oldest known and has been seen for 2,700 years, with the first recorded sighting being made by the Chinese in 687 BC.
So if you spot one or more Lyrids suddenly shoot across the sky, you will be sharing an experience from history, enjoyed by some of the earliest people to gaze at the stars in wonder.