Rare noctilucent clouds seen over Northern Ireland
Tuesday, June 4, 2013 - 08:00
in Astronomy & Space
Armagh Observatory reports that rare noctilucent clouds were observed over Northern Ireland on the night of the 30/31 May. The so-called "night shining" clouds take various forms ranging from delicate feathery structures to streamers, ripples and waves, and usually have a silvery grey or electric-blue colour. They are a summer phenomenon which can only be seen at night and when the Sun is between approximately 5 and 15 degrees below the observer's horizon. At our latitudes this means that they often appear low towards the northern horizon during the summer months May to August, either after sunset or before sunrise.