The term Supermoon is often used to describe when a full moon occurs while it is closest to the Earth during its elliptical orbit, which is known as “perigee” in astronomy.

Supermoon is not an actual astronomical term but was a term first coined by astrologer Richard Nolle in 1979 which he defines as a full moon or a new moon that is at or near (within 90% of) perigee, its closest point in its orbit . The correct astronomical term is Perigee-Syzygy moon where Syzygy refers to the alignment of the three celestial bodies (Sun, Earth, and Moon) which occurs during a new moon and a full moon.

The moon is approximately 12% closer in perigee which translates to 43,000 km (27,000 miles) than it is at apogee, or when the moon is at the furthest point away from the earth in its orbit. A supermoon appears approximately 30% brighter and 14% larger than a full moon in apogee and it often occurs once every 14 weeks.

Nolle, the creator of the term supermoon, claimed that it is the cause for natural disasters like earthquakes and hurricanes however other than increasing the tide by two inches above the regular tide levels, no scientific evidence was found to support the claim that a supermoon is the cause of natural disasters.