Following the Lyrids which peaked towards the end of April, it's now time for the Eta Aquariid meteor, which is set to reach its zenith tonight.
Will you be able to catch a glimpse of the Eta Aquariid meteor shower? Find out what triggers it and precisely when to keep an eye out for it, in the article below.
If you’re looking to make the most of the warmer evenings, why not check out our astronomy for beginnersguide and our UKfull 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?
Unfortunately, it's slim pickings if you want to see shooting stars from the Eta Aquariid meteor tonight.
Although the shower has a fairly long activity period of around five weeks, being active between 19 April and 28 May and peaking on the night of 5/6 May, viewing conditions are not ideal. Terrible, actually.
Not only does the meteor shower peak at the same time as the full Flower Moon, but the radiant does not rise very high before the onset of dawn.
So if we are lucky with meteors shooting up from the radiant and clearing the horizon, they will likely get drowned out by the Moon's light. 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 (very) 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 absolutely determined to spot a meteor from the Eta Aquariid shower this year (although you'll probably just end up enjoying the warm pre-dawn skies), here's how you can maximise your chances:
- If you can, try to avoid city lights and keep street lights away from your direct line of sight.
- Spend around 10-30 minutes outside to allow your eyes to adjust to the darkness, and use a red light filter (or red light torch) to help maintain your naturally accumulated night vision.
- Opt for a viewing location where the Moon is obscured, such as a spot where buildings or foliage block your view of it.
- Keep an eye out for meteor trains, which can linger in the sky for several seconds after the initial meteor has passed.
- Look out for fireballs, which are extremely bright and may be visible to several people at once. Although they are rare.
Where to look to see a shooting star (and what to see instead)
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).
For those of us in the UK, this means that the meteor shower will appear at a low altitude in the sky. There's a slim chance that we may be treated to meteors that appear to shoot up from the horizon, but it's almost a non-event.
Sorry, meteor hunters!
As dawn approaches, the radiant will climb higher in the sky, giving us a better opportunity. But of course, with the dawn – comes the Sun.
If you still want 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 astar-gazing app to help you out. Point your phone at, or below the horizon - and you'll see why it's such a difficult event to observe from the northern hemisphere.
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 when conditions are more favourable.
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?
Statistically speaking, when the Eta Aquariid meteor shower reaches its peak on 6 May 2023, the maximum zenithal hourly rate (ZHR) should 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 an extremely low-altitude radiant, we won't see anything even close to this many meteors, especially when you throw in a full Moon.
However, to add a slight glimmer of hope, 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 - although that's likely to be on one hand this year.
"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.
That's around 3 meteors per hour.
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.
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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