Where to look to see a Lyrid meteor shower

Lyrid meteors appear to emanate from the radiant position, southwest of bright Vega (Alpha (α) Lyrae), which can be found in the constellation Lyra.

Vega is also part of the informal star pattern – or asterism – known as the Summer Triangle.

This makes it particularly easy to trace a trail back to see whether it did indeed come from the radiant location.

Technically, the radiant sits in Hercules at the time of peak activity.

Zenithal Hourly Rate explained

Meteor showers are awkward in the world of astronomy.

Although you can predict when a shower’s peak period of activity will occur, you cannot specify exactly when and where individual meteor trails will be seen.

The number of trails expected during a shower’s peak period is expressed by a quantity known as the Zenithal Hourly Rate (ZHR).

A ZHR value is calculated by noting the number of shower meteors seen in a set period of time. Shower trails emanate from a small area of sky known as the shower radiant.

However, the ZHR value assumes perfect placement of the radiant, overhead at the zenith. Among other things, it also assumes perfect skies and your ability to see the entire sky in one view.

It varies depending on sky quality, date and time of day.

In practice, few of these conditions is met, so the experienced visual hourly rate (VHR) will be less than the quoted ZHR.

How to see a Lyrid meteor

To observe the Lyrid meteor shower:

• Find a place away from any stray lights
• Give yourself at 20 minutes in total darkness for your eyes to dark adapt
• Avoid looking at bright light sources such as a mobile phone
• Use a garden recliner or an astronomy chair that avoids you straining your neck to look upwards
• Stare up at an angle of about 60˚, two-thirds up the sky from horizon to zenith
• Look in any direction, but preferably the one in which the sky looks darkest.
• Aim to observe for periods of at least 30–60 minutes between short breaks.
• If you spot a meteor whose trail heads back towards the radiant point, you’ve seen a Lyrid!

What is a meteor shower?

We see a meteor in the sky when a small particle – on average about the same size as a grain of sand – vaporises in Earth’s atmosphere. The path of light across the sky is known as a meteor trail.

Most meteor showers are associated with comets, but some are linked with asteroids, such as the Geminid meteor shower, which is associated with 3200 Phaethon.

As a comet repeatedly orbits the Sun, it spreads dust around the orbit.

Earth passes through these dust streams as it orbits the Sun, causing particles to vaporise in the atmosphere. When this happens, the number of trails we can see increases.

We experience peak activity of meteor showers when Earth is passing through the most dense section of the stream.

Meteor trails appear to come from a specific area of the sky, which is known as the ‘radiant’. This slowly moves over the duration of the shower.

The constellation in which peak activity appears to occur is what gives each meteor shower its name. You might have heard of the Perseid meteor shower, for example, which shows peak activity when the radiant is in the constellation Perseus.

2023: a big year for meteor showers

This year is looking good for meteor showers, despite getting off to a poor start with an underwhelming showing from the January Quadrantids.

That was down to the presence of an almost full Moon around the shower’s peak period.

For the rest of 2023, however, the major meteor showers will enjoy moonless conditions during peak activity.

This includes the Lyrid meteor shower, Perseid meteor shower, Draconid meteor shower, Orionid meteor shower, Leonid meteor shower and the Geminid meteor shower.

This guide originally appeared in the April 2023 issue of BBC Sky at Night Magazine.

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