What you need to know about Friday’s rare blood moon eclipse

Astronomy Ireland gives the best times and locations to witness the celestial event

Around the world today a 'blood moon' will be seen as a result of the lunar eclipse. Here's all you need to know about it. Video: Enda O'Dowd


A blood moon will be visible across Ireland and much of the world on Friday night although heavy showers may prevent hopeful skygazers from seeing the rare eclipse.

The blood moon is a rare celestial event in which Earth appears in a straight line between the moon and the sun. The shadow of Earth’s atmosphere filtered through sunlight appears as a red sheen on the surface of the Moon.

It will be the longest lunar eclipse of the 21st century, lasting one hour, 42 minutes and 57 seconds.

Observers in the UK and Ireland will not be able to catch the start as the moon will still be below the horizon. The partial eclipse will be visible for almost four hours, however.

David Moore of Astronomy Ireland said the eclipse would “unfortunately be half over” before the moon rose here. From 9.30pm to 10.15pm it will be seen low in the south east. Then from 10.15pm to 11.20pm, the moon will be seen coming out of Earth’s shadow. After that, Mars – which is also red – would be visible just below the moon at its closest in 35 years, Mr Moore said.

Total eclipses of the sun and the moon are quite rare, but this one will be visible across large parts of the planet.

Best views

It will be best viewed between the tropics of Cancer and Capricorn but will also be partially visble in Europe and South America.

The moon will be just below the horizon when it occurs which means that in order to see the blood moon it will be necessary to go to a high point such as a hill or a mountain and look to the south-east horizon.

The blood moon will coincide with the spectacle of Mars, which is also red, making its closest approach to Earth for 35 years.

Unlike a solar eclipse, the lunar event can be viewed without wearing protective eyewear.

Dr Gregory Brown of the Royal Observatory Greenwich said: “As the entire eclipse will occur when the moon is fairly close to the horizon, the main thing to ensure is that you have a clear sightline to the south east.

“Try to find an open space or high hilltop clear of trees and tall buildings around you.”

Those awake after 11pm will also be able to catch a glimpse of the International Space Station (ISS), as it moves quickly across the sky from west to east.

Met Éireann said there will be showers during the late morning on Friday, extending eastwards. There will also be further heavy showers overnight, heaviest in the east and north later in the night.

In Britain, the Met Office has issued a thunderstorm warning from Friday afternoon due to last until just before midnight.

– Additional reporting: Agencies