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Supermoon Hype & Hoopla

The ballyhooed supermoon epithet has certainly generated all the attention that the media had hoped it would. Whether loved or despised, the nickname refers to a Full Moon or New Moon that's closer to Earth than the average Full Moon or New Moon. Yet, unbeknownst to many, a supermoon can be either a Full Moon - or a New Moon.

Few are aware of the origin of the term supermoon or its precise definition. This article seeks to remedy the confusion swirling around supermoon, which is entering into the public lexicon - whether we like it or not.

Even the great educator, Neil deGrasse Tyson, admits that he doesn't know who first called it a supermoon. And he is definitely second-guessing the definition by assuming a supermoon is strictly a Full Moon that coincides with lunar perigee - the Moon's closest point to Earth in its orbit.

Tyson dismisses the superlative as being out of place. Since any phase of the Moon can coincide with lunar perigee, why not give equal status to a super half-Moon, super crescent Moon, etc? In way of conclusion, Neil deGrasse Tyson correctly states that the Full Moon has no more tidal effect on Earth than any other phase of the Moon.

To the best of my knowledge, the term originated from the astrologer Richard Nolle, who defines a supermoon as a new or full moon which occurs with the Moon at or near (within 90% of) its closest approach to Earth. Given this definition, that gives us a total of five supermoons in the year 2014: two January 2014 New Moons and the Full Moons of July 12, August 10 and September 9, 2014.

In other words, the Full Moon or New Moon has to happen at or appreciably close to lunar perigee to be dubbed a supermoon, at least by Nolle's definition. However, lunar perigees are by no means equal throughout the year. The year's closest perigees occur when the Full Moon or New Moon coincides with lunar perigee. The year's farthest perigees take place when the Quarter Moons align with lunar perigee. The year's closest perigees come about 13,000 kilometers (8,000 miles) nearer to Earth than the year's farthest perigees.

Perigees and Apogees in 2014:

Image credit: Lunar Perigee and Apogee Calculator

This year's farthest and second-farthest perigees fall on November 27 and April 23, respectively. In April 2014, it's the Last Quarter Moon that's in close vicinity of lunar perigee; and in November 2014, it's the First Quarter Moon. Click here for a Moon phase almanac.

At Full Moon or New Moon, the Moon teams up with the Sun to create wide-ranging spring tides, whereby the high tide climbs up especially high and the low tide falls especially low on the same day. A perigee Full Moon or perigee New Moon accentuates the spring tide all the more, giving rise to a perigean spring tide.

By Nolle's definition, the New Moon or Full Moon has to come within 361,863 kilometers (224,851 miles) of our planet, as measured from the centers of the Moon and Earth, to be a supermoon in 2014. The Moon's closest approach to Earth for the year will come with the perigee Full Moon on August 10, 2014, coming to within 356,896 kilometers (221,765 miles) of Earth at lunar proxigee - the closest lunar perigee of the year.

What is a supermoon?

copyright 2014 by Bruce McClure

January 2014 Feature * March 2014 Feature