Largest supermoon in 70 years will be seen tomorrow

It's the first occurrence since 1948

A rare 'supermoon' will show the full lunar disc seem 14% and up to 30% brighter than usual as it rises above the rooftops on Monday.

The sight happens when a full moon is closest to Earth. It orbits our planet in an oval shape so sometimes it comes closer to us than at other times. This occurs about one in every 14 full moons, Jim Lattis, an astronomer at the University of Wisconsin Madison said.

At 11.23am Irish time on Monday the gap between the Earth and the moon will close to its shortest point, known as “perigee” — a distance of 356,510 km.

Skywatchers in the Ireland will have to wait a little longer before the full moon emerges in all its glory shortly before 5pm.

On top of the moon’s bigger than usual size, they will then be treated to an additional “low-hanging moon” effect.

This is an optical illusion caused by the moon being close to the horizon, where it can be measured against familiar objects such as trees and houses.

Monday’s event is the biggest and best in a series of three supermoons. The first was on October 16th and the third is due on December 14th.

Besides looking spectacular, the supermoon will give tides, which are affected by the gravity of the moon and sun, a small boost. High and low tides usually reach their peak during a full or new moon.