Eta Aquariids

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 4th-5th
Peak ZHR 10-30 from northern latitudes
Best Observed Rates Week around 5th May
Visibility each night (UK) Very limited visibility – radiant doesn’t rise until near dawn
Moonlight issues at Maximum None – New moon

Shower details – Radiant: 22:32 -1° – ZHR: 40 – Velocity: 42 miles/sec (swift – 66.9km/sec) – Parent Object: 1P/Halley

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 just before dawn (in morning twilight for observers in Scotland), few Eta Aquarid meteors, if any, are likely to be seen although as the shower has a broad maximum, keen observers may see some Eta Aquarids around a week either side of the maximum.

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

In 2013 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

Parent Body

This shower is one of two in the year that originates from Halley’s Comet, which was identified in 1705 by Edmond Halley as a periodic comet and goes by the proper name of 1P/Halley. The comet has been sighted for centuries, for example famously appearing on the Bayeux Tapestry. It revisits the Earth every 76 years and will be back in 2061.