The term “supermoon” is used to describe a new or full moon that occurs at roughly the same time the moon is nearest Earth in its monthly orbit.

If you want to sound more scientific, it is the perigee when the moon is at its closest point to Earth. You can sound more erudite by adding that it comes from the late 16th century French périgée, via modern Latin from Greek perigeion ‘close around the earth,’ from peri- ‘around’ + gē ‘earth.’


“Supermoon” is not a term that astronomers use. It is from astrology and is connected to the idea that the Moon (and so especially a supermoon) has an effect on not only the tides but on people. Richard Nolle coined the term more than 30 years ago, but it really caught on in this Internet age.

We had two supermoons in January – on January 1 and 30 – but they were new-moon supermoons. The full moons on July 12, August 10 and September 9 all enjoy the supermoon designation because the centers of these full moons and the center of Earth are less than 361,863 kilometers (224,851 miles) apart. Three in a row.  The closest supermoon of the year will be in August.