Supermoon to be visible over Ireland on Thursday night

Brighter, bigger ‘Flower Moon’ to rise in east half an hour after sunset

A “supermoon” will be visible over Ireland on Thursday night, according to Astronomy Ireland, with a brighter and larger appearance.

A supermoon is a full or “new” moon that appears when the moon is closest to the Earth in its orbit.

Ordinarily, the moon goes around the Earth in an orbit shaped like a slightly “squashed circle” called an ellipse. This means at times it can be about 15 per cent closer to the Earth than average, a factor which makes the moon look about 30 per cent brighter.

When a full moon coincides with the time it is at its closest distance to Earth, it is called a supermoon. The position of the moon at this time also gives it a slightly larger appearance than normal, as it is comparatively closer at hand.


The technical name is a perigee-syzygy or a full moon around perigee.

According to Astronomy Ireland, the best time to view the supermoon will be just after sunset on Thursday night. The supermoon will rise in the east about half an hour after sunset and will be visible throughout the night in the absence of cloud cover.

The disc-like appearance of the moon when viewed from Earth will appear larger than usual from anywhere it is visible across the country. “In fact, it will look bigger from anywhere in the world,” said Astronomy Ireland’s David Moore.

Flower Moon

In all, there are 12 “full moons” every year. This is where the word “month” came from as early civilisations broke the yearly calendar into the 12 moons of the year, Mr Moore said.

Each full moon has an unofficial folklore name, usually taken from North American folklore. The best known is the Harvest Moon in September, with the May full moon being known as the Flower Moon.

For those who miss the supermoon on Thursday, a fourth and final supermoon of 2021 will be visible on June 24th.

Astronomy Ireland magazine is also asking observers who take photos of the supermoon to send a copy into its monthly magazine. The magazine covers what to see in Irish skies every month and also publishes photographs and reports by members of the public about what has been seen in Irish skies.

"Many people get very creative around the time of supermoons and we want to publish the best of these photos in Astronomy Ireland magazine which will delight its thousands of readers around Ireland and will also ensure your photo is archived in the National Library of Ireland. So please email us your best photo or your written impressions of what you see to," said Mr Moore, who is also editor of the magazine.

Tim O'Brien

Tim O'Brien

Tim O'Brien is an Irish Times journalist