A BLUE SUPERMOON will be visible in Irish skies tonight and tomorrow, with stargazers being urged to get out and see the “extremely rare” event.

A supermoon occurs when a Full Moon happens around the time that the Moon is closest to Earth. 

This is because the Moon’s distance from the Earth can vary by 15%, which in turn causes a change in brightness of 30%, David Moore of Astronomy Ireland explained.

Moore said the best time to watch “is at Moon rise, which is the same time the Sun sets, when a further effect, called ‘The Moon Illusion’ kicks in which can make the Moon ‘look’ even bigger to the human eye/brain combination”.

This means the Moon will appear brighter and larger than normal.

The effect will be best seen tonight, though the supermoon will also be visible tomorrow night.

“Full Moons at this time of year are extremely low in the sky which is perfect for photos lining up landmarks, people, and events for the whole night”, Moore added, calling on the public to send in their photos to Astronomy Ireland.

Speaking on Morning Ireland today, Moore explained that there are normally 12 Moons in a year, but sometimes there can be 13. “When you have a season that squeezes four Full Moons in instead of three”, he continued, “the third one is called a Blue Moon because it’s so rare”.

The combination of a Blue Moon and supermoon is what makes the event over the next couple of nights “more special”.

Those who miss this week’s show will have to wait eight years for the next blue supermoon, with the next one not occurring until 2032. 

Views may be disrupted, however, by the band of rain tracking across the country tonight, with some heavy and thundery downpours possible. 

Tomorrow night will be largely dry with some clear spells, though clouds will build from the west later in the night.