2018 Eta Aquarids

A good shower from the southern hemisphere, but is barely observable from the UK.

Main Activity Dates Apr 19 to May 28
Peak Rates May 5–6
Peak ZHR 50 – 70
Best Observed Rates Pre-dawn on May 6
Visibility each night (UK) Very limited visibility – radiant doesn’t rise until near dawn
Moonlight issues at Maximum Major – last-quarter Moon near radiant

The Eta Aquarid meteor shower – the post-perihelion encounter with the meteor stream of comet 1P/Halley – has tended to be ignored by UK observers. With the radiant only starting to rise above the eastern horizon late in the night (in morning twilight for observers in Scotland), few Eta Aquarid meteors, if any, are likely to be seen, particularly in 2018.

In 2013, however, the Eta Aquarids sprang a surprise and several Eta Aquarid meteors were imaged from the UK by Alex Pratt (see our special report) and William Stewart of the NEMETODE network (www.nemetode.org). This enhanced activity tied in with a last minute prediction from Mikiya Sato that the Earth would encounter several old filaments (from 8-11 centuries ago) in the Eta Aquarid meteor stream during May 6th.

No enhancement of rates was expected or seen in 2014, 2015, 2016 or 2017.

At maximum, the Eta Aquarid radiant lies at RA 22h32m , Dec –01º  – in the top left corner of Aquarius (see the chart below)

Eta Aquarid chart
Eta Aquarid chart

In 2018 the last-quarter Moon will be close to the radiant on the night of maximum, so only the brightest meteors will be visible. However, as the shower has a broad maximum, keen observers may see some Eta Aquarids around a week after the date of maximum, when the Moon has waned considerably.

Eta Aquarids are very swift meteors, often with long paths because of their low radiant, and fine persistent trains.