... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . Armagh Observatory reports that rare noctilucent clouds were observed over Northern Ireland on the night of the 30/31 May. ... The origin of noctilucent clouds remains a mystery. ... One of the many puzzles surrounding noctilucent clouds is that they appear to be a relatively recent meteorological phenomenon, first described as a distinct cloud phenomenon by the astronomer and meteorologist Thomas William Backhouse in 1885. ...