A meteor shower that stands out against the relatively low springtime meteor rates
|Main Activity Dates||Apr 16–28|
|Peak Rates||Apr 22d 17h UT|
|Best Observed Rates||Night of Apr 21-22|
|Visibility each night (UK)||Visible all night|
|Moonlight issues at Maximum||Medium – first quarter|
Background meteor rates are generally low for northern hemisphere based observers during the first half of the year. The Lyrids stand out above this. The peak ZHR is normally ~15-20, but short-lived, more active bursts have been recorded sometimes, most recently in 1982 (when ZHRs were ~90). Lyrid meteors are typically medium to swift speed. The parent body is Comet Thatcher of 1861 (whose orbital period is about 415 years).
In 2018, Lyrid maximum is predicted for approx 17h UT on April 22. From the UK, the best rates are likely to be seen just before dawn on April 22. However, for those observers who prefer late evening and early morning observations, the night of April 22-23 will probably be equally as good. With the Lyrid peak being broader than that of the Quadrantids, the early evening prediction for the peak is less detrimental to observed rates in the following morning skies.
The Moon is at first quarter and sets after 2h UT on 22 April. So although the rate is then starting to decline, the increased radiant height and lack of moonlight after this time will compensate.
The Lyrid radiant (see chart below), lies on the Hercules-Lyra border at the peak (and not quite as near Vega as some people expect). It is low in the sky at the start of the night and gains altitude as the night progresses, leading to increasing observed rates. The chart below shows how it has climbed well clear of the horizon and is quite high in the eastern sky by the early hours of the morning.