- The 2027 Eta Aquariids peak on the night of 5 May–6 May; active 19 Apr – 28 May.
- Up to 50 meteors an hour in a perfect sky; on the peak night in London about 5 from a dark site, about 1 from town.
- The Moon will not interfere: the sky will be dark.
- The radiant is in Aquarius, highest around 03:40.
- Source: 1P/Halley; speed 66 km/s.
When to look in 2027
The Eta Aquariids are active from 19 Apr to 28 May. The curve shows activity rising and falling, the dots under it how much of the Moon is lit each night.
Night by night
For each night the best hour is computed: the radiant high, the sky dark, the Moon in the way least. A dark site means out of town where the faintest stars show; town means a bright suburban sky.
| Night | ZHR | Moon | Best | Dark site | Town |
|---|---|---|---|---|---|
| Thu 29 Apr | 17 | 38 % | 04:00 | 1 | <1 |
| Fri 30 Apr | 20 | 29 % | 04:00 | 2 | <1 |
| Sat 1 May | 24 | 20 % | 03:40 | 2 | <1 |
| Sun 2 May | 29 | 13 % | 03:40 | 2 | <1 |
| Mon 3 May | 34 | 7 % | 03:40 | 3 | <1 |
| Tue 4 May | 41 | 2 % | 03:40 | 4 | 1 |
| Wed 5 MayPeakmost meteors | 49 | 0 % | 03:40 | 5 | 1 |
| Thu 6 May | 43 | 1 % | 03:40 | 5 | 1 |
| Fri 7 May | 36 | 4 % | 03:40 | 4 | 1 |
| Sat 8 May | 30 | 9 % | 03:40 | 4 | <1 |
| Sun 9 May | 25 | 17 % | 03:20 | 2 | <1 |
| Mon 10 May | 21 | 27 % | 03:20 | 2 | <1 |
| Tue 11 May | 18 | 38 % | 03:20 | 2 | <1 |
Where to look
The meteors fly out of the radiant in Aquarius. In London it rises around 02:40 and is highest while dark, 9°, around 03:40.
You do not have to look at the radiant itself: meteors appear all over the sky, and the longest ones 40–60° away from it. Lie back, take in as much sky as you can and stay with it for 20–30 minutes so your eyes adapt.
Where they come from
The Eta Aquariids are dust from the same Halley's Comet as the October Orionids: the Earth crosses the comet's stream twice a year. In May it meets the stream from the other side, and the meteors arrive at 66 km/s.
History
In the southern hemisphere this is one of the finest showers of the year, with 50 or more meteors an hour. Activity varies on a cycle of about 12 years, set by Jupiter's pull on the dust stream.
What they look like and how to watch
From northern Europe the radiant in Aquarius rises only just before dawn and stays very low, so only a few meteors show. If you try, face south-east in the last hour before it gets light: that is when long, horizon-grazing meteors appear.
How many meteors you will really see
The ZHR (50) is how many meteors an observer would see in an hour in a perfectly dark sky with the radiant straight overhead. The real count is always lower: the lower the radiant, the more meteors stay below the horizon, and every step of sky brightness hides the faintest ones.
This page uses the International Meteor Organization formula: hourly rate = ZHR × sine of the radiant altitude ÷ r^(6.5 − limiting magnitude). For this shower r = 2.4. A dark site is taken as showing stars to magnitude 6.0, a town to 4.5; moonlight takes off up to 1.8 magnitudes.
How to photograph a meteor
You need a camera with manual mode and a tripod. Wide-angle lens (14–24 mm), aperture wide open (f/1.8–f/2.8), ISO 1600–3200, exposures of 15–25 seconds. Focus manually on a bright star and tape the ring.
Shoot continuously with an intervalometer or remote, frame after frame for an hour or more. Meteors are random, so patience wins: one or two an hour is a normal catch. Aim 40–60° from the radiant, above the glow of the horizon.
Dates in the coming years
| Year | Peak | Moon |
|---|---|---|
| 2028 | Friday · 5 May 2028 | 85 % |
| 2029 | Saturday · 5 May 2029 | 47 % |
| 2030 | Sunday · 5 May 2030 | 10 % |
| 2031 | Monday · 5 May 2031 | 99 % |
| 2032 | Tuesday · 4 May 2032 | 20 % |
| 2033 | Thursday · 5 May 2033 | 44 % |
Other meteor showers
Questions people ask
When are the Eta Aquariids in 2027?
The peak is on the night of 5 May–6 May. The shower is active from 19 Apr to 28 May, so meteors show for several nights before and after.
What time is best?
In London on the peak night, around 03:40, when the radiant is 9° up and the Moon interferes least.
How many meteors will I see?
A ZHR of 50 is the perfect-sky figure. In London on the peak night expect about 5 an hour from a dark site and about 1 from town.
Which way should I look?
Meteors come from the direction of Aquarius but appear all over the sky. Look 40–60° away from the radiant, at the darkest part of the sky.
What causes the Eta Aquariids?
Dust left by 1P/Halley. The Earth crosses the stream at the same time every year, and the grains burn up in the atmosphere at 66 km/s.
Will the Moon get in the way?
The Moon will not interfere: the sky will be dark.
- International Meteor Organization, Meteor Shower Calendar: activity periods, solar longitudes of the peaks, ZHR, population index.
- IMO Visual Observing Handbook: the hourly rate formula (ZHR, radiant altitude, limiting magnitude).
- Astronomy Engine (Don Cross): positions of the Sun, the Moon and the radiant.
- JPL Small-Body Database: comet and asteroid orbits.
The peak date is computed from the Sun's ecliptic longitude. The activity curve is the IMO model ZHR(λ) = ZHRmax · 10^(−B·|λ − λmax|). For each night the radiant altitude and the Sun and Moon are computed every 20 minutes; the hour with the highest expected count is shown.