A so-called "supermoon" will be visible in skies over Ireland for the next two nights. During this period, the moon appears much larger and brighter than usual.
The moon's orbit around the earth is an ellipse, not a perfect circle, so it's sometimes closer, and sometimes farther away.
A supermoon occurs when a full moon coincides with the time when the moon is closest to the earth in its orbit - resulting in a moon that is 14% larger to the eye and 30% brighter
David Moore of Astronomy Ireland said if skies are clear, Ireland should get a particularly good view.
"The full moon will always be low-down - there's actually an optical illusion as well that makes it look bigger when it's on the horizon - so we'll have a with the moon illusion on the horizon," he said.
"So, from Ireland, this far north, we'll get a double effect - and it certainly will be 30% brighter."