The Lyrids meteor shower
Key facts
- Peak
- around 22–23 April
- Active
- about 14–30 April
- Rate at peak (ZHR)
- about 18 (occasional outbursts near 100)
- Speed
- 49 km/s
- Radiant
- Lyra (near the bright star Vega)
- Parent body
- Comet C/1861 G1 (Thatcher)
Dates shift slightly from year to year. This year's peak is in the events calendar.
The Lyrids are the oldest meteor shower in the historical record. Chinese chroniclers described stars falling "like rain" in the year 687 BC, and astronomers today accept that as an early Lyrid display. For a shower to be noticed and written down more than 2,700 years ago is a reminder that people have always watched the night sky with care.
In an ordinary year the Lyrids are modest. They break a long lull: from mid-January to mid-April there are no strong showers at all, so April's meteors are a welcome sign that the meteor year is waking up. Under a dark sky at the peak you might see 10 to 20 an hour. Every so often, though, the Earth passes through a denser clump of dust and the shower briefly surges. Observers in the United States reported a remarkable display in 1803, and bursts of activity were seen in 1922 and again in 1982, when rates rose close to 100 an hour for a short time. Outbursts like these are very hard to predict, which is part of the fun.
The parent comet. The Lyrids come from Comet Thatcher, officially C/1861 G1, discovered in April 1861 by the American amateur astronomer A. E. Thatcher. It is a long-period comet, meaning it takes a very long time to orbit the Sun. Its period is about 415 years, so it will not return until the 2270s. Each time it swept through the inner Solar System it shed dust along its path, and every April the Earth crosses that trail. The particles are tiny, most no bigger than a grain of sand, and they burn up about 80 to 100 km above the ground.
What to expect. Lyrids enter the atmosphere at about 49 km/s, a medium-to-fast speed. Many are faint, but the shower is known for a fair share of bright meteors, and some leave glowing trains (trails of ionised gas) that linger for a second or two. The radiant lies close to Vega, one of the brightest stars in the northern sky, which makes it easy to find.
Viewing from the UK. The UK is well placed. Lyra rises in the north-east during the evening and climbs high by the early hours, so the best time is after midnight and before dawn begins. April nights are shorter than winter ones but still give several hours of darkness. It is often chilly, so wrap up. Look for Vega as a brilliant blue-white star high in the east before dawn; meteors can appear anywhere, but if you trace their paths backwards they will point back towards it.
Viewing worldwide. The Lyrids favour the northern hemisphere, but observers in the southern hemisphere can still see some, especially from the tropics and subtropics, in the hours before dawn when Vega has risen. The further south you are, the lower the radiant and the fewer meteors you will see.
The Moon's phase matters a great deal for a modest shower like this. A bright Moon near the peak can wash out all but the brightest meteors, while a dark sky can make an ordinary year surprisingly rewarding. Peak dates vary by about a day from year to year.
Viewing tips
- Find Vega, a bright blue-white star, to locate the radiant, high in the east after midnight.
- Watch in the hours after midnight, when Lyra is high and the sky is darkest.
- Check the Moon's phase: a moonless night makes a big difference for this modest shower.
- Keep watching for a while, because Lyrid outbursts are rare but unpredictable.
- Lie back on a reclining chair so you can take in as much sky as possible.
Read about the parent: Comet Thatcher, and the other comets behind meteor showers.