If you’re keen to spot remnants of arguably one of the most famous comets (in the form of some spectacular shooting stars), then now’s your chance. The Eta Aquariids are in full swing, and conditions are looking good for viewing this meteor shower at its peak.
When is the best time to see this meteor shower? Which direction should you look? We have the answers, just for you, below.
If the Eta Aquariids have whetted your appetite for more meteor shower action this year, be sure to check out our 2024 meteor shower calendar for all the facts and information. Or perhaps you’re keen to spot the comets themselves? Although we’ve got a long wait until Halley’s Comet returns to our skies (37 years and counting), you can still see these brightest comets of 2024.
When is the best time to see the Eta Aquariid meteor shower in 2024?
The best time to see the Eta Aquariids is in the early hours of 6 May 2024 in the UK and US. Watching from around 2am until dawn (at 5:22am BST in the UK) will yield the best results (if the clouds hold).
Conditions are good this year; there’s a new Moon on the night after the meteor shower peaks. And with the Moon out the way, there’s no natural interfering light, like there was for the Lyrids in April.
The Eta Aquariids began on 19 April and will continue through until 28 May. Although most activity will be centred around the peak on 6 May, the meteor shower is also known to produce decent displays for a few days on either side of the peak.
Where to look
Look towards the southeastern horizon in the pre-dawn hours. In a meteor shower, shooting stars will originate from one point in the sky (known as the radiant) – in this case, the Water Jar asterism in the constellation Aquarius. However, meteors will streak across all parts of the sky.
If possible, try to take in as wide a field of view when observing, and be patient. Look around at the other nearby constellations.
Meteors nearer the radiant have shorter trains, making the already tricky meteors even trickier to spot. Looking only towards the radiant may cause you to miss some of the better, more spectacular meteors.
How to find Aquarius in the night sky
Since Hubert A Newton began his observations of various historical meteor showers in 1863, the position of the radiant – the constellation Aquarius – has remained relatively constant.
To find the radiant, look towards the east and 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 stars in the constellation.
Draw an imaginary line between these two stars, then extend it down 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 (or it’s below the horizon), there are plenty of star-gazing apps to help you out. Point your phone at – or below – the eastern horizon, and you'll find Aquarius loitering between Pisces further towards the east, and Capricornus further towards the south.
How many meteors can you expect to see?
The Eta Aquariids are a moderately active shower, with a maximum rate of about 50 meteors per hour. However, this is assuming ‘perfect’ conditions; dark skies and a radiant that is high overhead.
The radiant is the point in the sky where the meteors appear to originate. Generally speaking, the higher the radiant is in the sky, the ‘better’ the display will be as the Earth turns to face the oncoming meteors.
Eta Aquariid meteor shower: Viewing tips
If you're keen to spot an Eta Aquariid meteor, here's how you can maximise your chances:
- Avoid bright lights: If you can, avoid city lights and keep streetlights away from your direct line of sight.
- Let your eyes adjust: Spend around 10-30 minutes outside to allow your eyes to adjust to the darkness.
- Use a red-light filter: If you need to look at your phone, use a red-light filter. This will avoid disrupting your accumulated night vision.
- Watch out for Earth-grazers and trains: Keep an eye out for meteor trains. They can linger in the sky for several seconds after the initial meteor has passed.
- Get comfy: A reclining chair or hammock is ideal for avoiding the mud underfoot.
- Be patient: With the radiant so low on the horizon, you’ll need to be patient. But your patience will be rewarded if you manage to spot an Earth-grazer.
Why this year's shower will be difficult to spot
Shooting stars in the Eta Aquariid meteor shower will originate at a point in the sky (known as the radius) in the constellation of Aquarius. But here’s the problem; Aquarius doesn’t rise until the morning twilight. It starts to peep above the horizon from around 2:30am BST, but even by 4:30am is still not fully risen. This means that all but the brightest meteors will be lost in the gradually brightening sky.
As such, it’s a relatively tricky shower to observe from the northern hemisphere. Southern hemisphere viewers will have better luck. In Australia, for example, Aquarius rises around 2am AEST (Australian Eastern Standard Time), providing several decent hours of meteor shower action.
Realistically, for those of us in the northern hemisphere, the number of meteors we can expect to see will be much less than the maximum rate of 50. But with the Moon out of the way, conditions this year are favourable.
We can expect to see perhaps between a handful of meteors per hour (unless Jupiter has other ideas, more on that below) up to around 30.
The radiant will reach its highest point just before midday, when of course, it’s not visible to our human eyes. But this meteor shower has produced spectacular outbursts in the past.
The Springhill Meteor Observatory, located near Ottawa, used radar (radio-echo) techniques to detect the shower's peak activity between 1958 and 1967. They recorded as many as 500 meteors per hour!
How to see 'Earth-grazer' meteors
Before you write this shower off completely, around a quarter of these meteors could produce lingering trails in the sky. And with the radiant below the horizon, we may be treated to a few ‘Earth-grazers’.
These are meteors that skim the Earth's atmosphere, creating long streaks across the sky. Earth-grazers are particularly notable during this shower's peak. Although less frequent than other types of meteors, they can be breathtaking to witness.
Following a path that’s nearly parallel to our atmosphere, Earth-grazers enter the atmosphere at a shallow angle. And it’s this shallow angle that allows the magic to happen.
It means the debris travels a longer way through the atmosphere before burning up. This longer journey allows the meteoroid to ionize and excite more air molecules along its path, creating a longer-lasting and more visible trail. It slows down, too.
It’s this combination of the meteoroid's slower speed and the longer interaction with our atmosphere that results in the luscious long streaks.
Jupiter may increase meteor shower activity this year
Astronomers modelling the meteor shower’s intensity from 1985 to the present day, are tentatively hinting that we may see increased activity this year (and in 2045 – but we can’t think that far ahead right now).
Using a new numerical model, they’ve been running the numbers on the origin, variability and age of both the Eta Aquariids and the Orionids, in order to predict activity over the next few decades.
Are they right? The only way we’ll know is in hindsight, so it might be worth making an effort to brew the coffee extra early. Just in case.
According to the American Meteor Society, this increased activity could be “quite strong” due to interactions of the debris trail with the planet Jupiter.
What causes the Eta Aquariid meteor shower?
The parent comet for the Eta Aquariid meteor shower is 1P/Halley, more commonly known as Halley's Comet.
A periodic comet (where one orbit around the sun is less than 200 years) made of volatile ice and dust, Halley’s Comet orbits the Sun once every 76-ish years. As it makes its way through the inner Solar System this ice and dust evaporates, leaving behind a trail of debris.
When Earth passes through this debris field, the particles enter our atmosphere and disintegrate. This results in the bright streaks that we see as meteors.
There are two showers associated with Halley’s Comet, the Eta Aquariids in May and the Orionids in October, as Earth intersects with the ‘other side’ of Halley’s orbital path around the Sun.
Halley’s Comet has a highly elliptical orbit, which stretches out beyond Neptune at its furthest point. It’s also a retrograde orbit, meaning that it orbits the Sun in the opposite direction to Earth and the other planets.
Meteoroids from Halley’s Comet enter Earth’s atmosphere at relatively fast speeds (around 66km/s or 41miles/s). They appear as fast streaks, the brightest leaving long-lasting trains.
The Eta Aquariids are typically better seen from the southern hemisphere, while the Orionids are visible from both hemispheres.
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