Universe Today
Early May is a good time to watch for a powerful yet often elusive meteor shower, the annual Eta Aquariids.
They’re a prolific, yet often elusive for northern hemisphere observers. If skies are clear, watch for a strong annual meteor shower that’s attained an almost mythical status: the May Eta Aquariids.
The Eta Aquariid meteor shower is active from April 19th until May 28th, with the key night being the evening of May 5th into the morning of May 6th. This is a strong shower, with a Zenithal Hourly Rate (ZHR) topping out on some years at 60-100 meteors an hour. The Eta Aquariids actually take third place in terms of strong annual meteor showers, right behind the August Perseids and the December Geminids. The shower has a broad peak, and produces swift moving (65.4 kilometers a second) meteors often leaving glowing, persistent trains.
But the May Eta Aquariids have a PR problem, at least in the eyes of northern hemisphere observers. First off, the Eta Aquariids are a rare, southern hemisphere shower. The radiant sits at one degree of declination, just below the celestial equator near the +4th magnitude star Eta Aquarii in the Y-shaped Water Jar asterism.
The position of the radiant for the Eta Aquarid meteors. Credit: Stellarium.
This means that the radiant only rises around 2AM local, and transits the meridian highest in the sky around 8AM, post-sunrise. Arriving just over a month prior to the June Solstice gives northern viewers only a slender window of darkness to nab members of the shower.
A pair of Eta Aquariid meteors over Fort Jefferson in the Florida Keys from 2019. Credit: Jeff Berkes.
But it’s now fall headed into winter Down Under. I’ve heard Australians mention that, for them, the Eta Aquariids are one of the best annual meteors of the year, with the radiant riding high in the sky. The South may have all the good star clusters and galactic targets, but the North seems to have a wealth of major meteor showers.
The Eta Aquariids as seen from Chile. Credit: ESO/P. Horalek.
There’s no reason to suggest why this cosmic coincidence exists. Of the 13 major annual meteor showers, only two (the other one also occurring in Aquarius, the August Delta Aquariids) have a radiant in the southern hemisphere. Ironically, the south always seems to get all of the good bright comets, such as the currently bright Comet C/2025 R3 Pan-STARRS.
Meteor showers in 2026. Credit: Dave Dickinson.
Prospects for the Eta Aquariids in 2026
Rates seem to hover around 50 meteors an hour on most years, but the Eta Aquariids have surprised us in the past. 2013, for example, saw a fine show, with rates topping 140 per hour.
The source of the Eta Aquariids is none other than that most famous of all comets: 1P/Halley. On a 74.7 year orbit, Halley’s Comet last swung through the inner solar system in 1986, and will do so again in 2061. The comet actually reached aphelion 35 Astronomical Units (AU) from the Sun on December 9th, 2023. Halley’s Comet is also the source of another prodigious northern shower: the October Orionids.
A family portrait, of an Eta Aquariid meteor and Halley's Comet. Credit: Frankie Lucena.
We’re actually well out of the path of Halley’s Comet, as the meteors we see in the two annual showers that now intersect the Earth were laid down thousands of years ago. Outbursts from the comet were more frequent in the 5th and 10th centuries AD.
Tips on Beating the Moon
Now for the bad news: 2026 sees the Eta Aquariids doing battle with the waning gibbous Moon, -84% illuminated and just four days past Full. A good way to curtail the Moon’s impact on the number meteors you’ll see is to position your observing site so that the Moon is physically blocked from view behind a building or hill.
It’s great to think, that though the next apparition of Halley’s Comet is still decades away, we can still enjoy its ancient progeny as we watch the May Eta Aquariids streak silently across the pre-dawn sky.
