Meteor shower tonight: How to see the May 2023 Eta Aquariid shooting stars

Here’s how to get the most from this year’s poor viewing conditions.

By Holly Spanner

Published: Wednesday, 03 May 2023 at 12:00 am

Following the Lyrids which peaked towards the end of April, it’s now time for the Eta Aquariid meteor. While you may be able to you some shooting stars tonight, the celestial spectacle is anticipated to reach its zenith later this week.

To ensure you catch a glimpse of the Eta Aquariid meteor shower, what triggers it, and precisely when to keep an eye out for it, read on for all the answers and more.

If you’re looking to make the most of the warmer evenings, why not check out our astronomy for beginners guide and our UK full Moon calendar? For a full roundup of this year’s meteor showers, we’ve put together a list of all the events visible from the UK in our meteor shower calendar.

When can you see the Eta Aquariid meteor shower 2023?

The Eta Aquariid meteor shower has a fairly long activity period of around five weeks, and is active between 19 April and 28 May, peaking on the night of 5/6 May.

Viewing conditions are not ideal this year, however, as the meteor shower peaks at the same time as the full Flower Moon. When the sky is too bright, meteors get drowned out by the Moon’s light, so where possible, it’s better to look to the night sky during a new Moon, or crescent Moon phase.

“Since the light of the Full Moon will completely outshine all but the brightest of these shooting stars, it will be best to wait a few weeks for moonlight to stop interfering and take a look then instead,” advises Dr Darren Baskill, astronomy lecturer at the University of Sussex.

However, if you’re feeling lucky and want to brave the light of the full Moon, head out just before sunrise on the morning of Saturday 6 May.

How to maximise your chance of spotting a meteor tonight

If you’re determined to spot a meteor from the Eta Aquariid shower this year, here’s how you can maximise your chances, despite the full Moon:

Where to look to see a shooting star

The Eta Aquariids are visible from both hemispheres, although viewing favours the southern hemisphere. This is because the radiant – the point from which the meteors appear to originate – is near the celestial equator, close to the Water Jar asterism in the constellation Aquarius.

“Unfortunately, this meteor shower is not favourable for those of us in the UK for another reason [aside from the full Moon].  The meteors will appear to originate from a point below the horizon, as the Earth is travelling in that direction as it orbits around the Sun.  This means that, for observers in the UK, the majority of shooting stars will be hidden below the horizon,” explains Baskill.

But there are other sights to look out for, and you may also be able to glimpse Saturn, as it lurks near to the double star Sigma Aquarii. Aquarius itself only starts to peep above the eastern horizon from around 2am, and is not fully risen by the time the Sun rises at 5:23am (UK time).

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The radiant of the Eta Aquariid meteor shower is located in the constellation Aquarius, which is low on the eastern horizon just before dawn © NASA/ESA/ESO/Space Telescope Science Institute/IAU Minor Planet Center/Fabien Chereau/ Noctua Software

For those of us in the UK, this means that the meteor shower will appear at a low altitude in the sky, so we may be treated to meteors that appear to shoot up from the horizon. As dawn approaches, the radiant will climb higher in the sky, giving us a better opportunity.

To find the radiant, locate the two stars in the Great Square of Pegasus, the red giant Beta Pegasi (aka Scheat) and Alpha Pegasi (aka Markab) – these are the top-most and the right-hand star in the constellation.

Draw an imaginary line between these two stars and extend it for about the same distance again. Near here is the faint star Eta Aquarii, marking the apparent position of the radiant.

If you’re having trouble picking out Eta Aquarii, you could always use a star-gazing app to help you out.

Since Hubert A Newton’s observations of a series of historical meteor showers began in 1863, the position of the radiant for the Eta Aquariids has remained relatively constant. As a result, once you’ve got your eye on where to look, you’ll be a pro for next year. In 2024, we can expect much better conditions thanks to the peak being centred around a nice, dark new Moon.

How many meteors will you be able to see?

When the Eta Aquariid meteor shower reaches its peak on 6 May 2023, the maximum zenithal hourly rate (ZHR) will be around 60 meteors per hour. However, the ZHR calculation assumes ideal conditions; clear skies and no light pollution, with the radiant directly overhead. Since the Eta Aquariids have a low-altitude radiant, it’s unlikely that we will observe this many meteors, especially when you throw in a full Moon.

However, it is anticipated that approximately 25 per cent of these meteors will produce lingering trains in the sky. A tally counter is a useful way to keep track of the number you witness.

“I would expect us to see a meteor every 10 to 20 minutes, from a dark location under clear skies in mid-May,” says Baskill.

The radiant of the Eta Aquariid meteor shower is at its highest point in the sky just before midday, but it is not visible during daylight hours. However, the Springhill Meteor Observatory, located near Ottawa, used radar (radio-echo) techniques to detect the shower’s peak activity between 1958 and 1967, observing as many as 500 meteors per hour.

Where do the Eta Aquariids come from?

The Eta Aquarids are created by debris left behind by 1P/Halley, more commonly known as Halley’s Comet, which orbits the Sun once every 76 years. As the comet travels through the inner solar system, ice and dust in the comet evaporate, leaving a trail of debris in its wake. When the Earth passes through this debris trail, the particles enter our atmosphere and disintegrate, leaving bright streaks in the sky that we see as meteors.

There are two meteor showers associated with Halley’s Comet; the Eta Aquariids in May and the Orionids in October. This is because Halley’s Comet is in a retrograde orbit (orbiting the Sun in the opposite direction to Earth) and intersects with different parts of the comet’s debris trail around the Sun.

Halley’s Comet is composed of a mixture of volatile ice and dust, making it a crumbly ‘dirty snowball’ comet. It has been orbiting the Sun for at least 16,000 years, all the while leaving behind a trail of debris along its path. Its orbit is highly elliptical, like an elongated oval shape that stretches out beyond Neptune’s orbit at its farthest point.

Because of its retrograde orbit, meteoroids from Halley’s Comet enter Earth’s atmosphere at relatively fast speeds of around 66km/s. For observers here on Earth, this means they will appear as fast streaks, the brightest leaving long-lasting trains.

Observing the Eta Aquariid Meteor Shower: Viewing tips

If you can, find an area away from light pollution. Although night temperatures on the 5/6 May are expected to be fairly mild – around 11 to 12°C from London – we are due some light cloud cover and a spot of rain, so be sure to check your local weather forecast.

Assuming the weather is clear, it’s best to lie back on a reclining chair, hammock, or blanket and allow your eyes to adapt to the darkness for at least 10 to 20 minutes.

With time and some patience, you’ll gradually get used to spotting the meteor trails as they dart across the sky. While observing, it’s advisable to avoid looking at other intense sources of light such as your mobile phone. However, if you must, it’s best to use a red filter or a red light torch.

About our expert, Dr Darren Baskill

Darren is an outreach officer and lecturer in the department of physics and astronomy at the University of Sussex. He previously lectured at the Royal Observatory Greenwich, where he also initiated the annual Astronomy Photographer of the Year competition. 

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