The rare transition of Mercury between the earth and the sun, where the two planets will align perfectly is happening today.
It will take place between 12:12 pm and 7:42 pm and will look like a small black dot travelling across of the sun.
It is STRONGLY advised to use a telescope or a pair of binoculars with a solar filter. Otherwise staring directly at the sun will badly damage eyesight and could lead to blindness.
Mercury orbits the sun at a far greater pace than Earth. It orbits the sun every 90 days but the planets are always misaligned and are not visible to us.
David Moore of Astronomy Ireland said: “For a lot of us it is a once in a lifetime event”. The last time it could be viewed was 2003 but unfortunately the sky was cloudy and the next viewing will be 2049.
For anyone wishing to see it, the weather is set to be good and not cloudy.