Rare 'blue supermoon' to be visible in skies

Despite its name, a blue moon does not indicate the colour, but refers to the timing of full moons through the year.

There are two different definitions – the third full moon is an astronomical season or two full moons within a calendar month.

This full moon is the second one this month, making it a ‘blue moon.’

It will also be a Supermoon, which, according to NASA, is when the Moon’s orbit is closest (perigee) to Earth at the same time the Moon is full.

The outline how the term “supermoon” was coined in 1979 and’ is often used to describe what astronomers would call a perigean full moon: a full moon occurring near or at the time when the Moon is at the closest point in its orbit around Earth.”

When a full moon appears at perigee it is slightly brighter and larger than a regular full moon – a ‘supermoon.’

Blue moons and supermoons don’t always appear together – making tonight and tomorrow’s event a rare one. Based on predictions, the next blue supermoon probably won’t happen until 2037.

Astronomy Ireland is encouraging everyone to take a picture, even with your smartphone, if they see tonight’s ‘blue supermoon’ and send it to [email protected].

Sightings could be hampered however, by cloud cover. Met Eireann has forecast a band of showery rain will move into western areas and track eastwards across the country overnight, with some heavy or thundery falls possible.