BY Tracy Miller
DAILY NEWS STAFF WRITER
Tonight’s moon is the second full moon of December; the first occurred Dec. 2.
Though the expression “once in a blue moon” is used to describe extremely rare events, blue moons aren’t all that unusual, occurring every 21/2 years or so. But a New Year’s Eve blue moon is somewhat more remarkable — we haven’t had one since 1990.
Fact and fantasy about blue Moons.
by Philip Hiscock
“According to old folklore,” some people say, the second full Moon in a calendar month is called a “blue Moon.” They go on to explain that this is the origin of the expression “once in a blue Moon.” But it isn’t true! The term “blue Moon” has been around a long time, well over 400 years, but its calendrical meaning has become widespread only in the last 20 years.
A Variety of Meanings
In fact, the very earliest uses of the term were remarkably like saying the Moon is made of green cheese. Both were obvious absurdities, about which there could be no doubt. “He would argue the Moon was blue” was taken by the average person of the 16th century as we take “He’d argue that black is white.”
The concept that a blue Moon was absurd (the first meaning) led eventually to a second meaning, that of “never.” The statement “I’ll marry you, m’lady, when the Moon is blue!” would not have been taken as a betrothal in the 18th century.
But there are also historical examples of the Moon actually turning blue. That’s the third meaning — the Moon appearing blue in the sky. When the Indonesian volcano Krakatoa exploded in 1883, its dust turned sunsets green and the Moon blue all around the world for the best part of two years. In 1927, the Indian monsoons were late arriving and the extra-long dry season blew up enough dust for a blue Moon. And Moons in northeastern North America turned blue in 1951 when huge forest fires in western Canada threw smoke particles up into the sky.
So, by the mid-19th century, it was clear that visibly blue Moons, though rare, did happen from time to time — whence the phrase “once in a blue Moon.” It meant then exactly what it means today, a fairly infrequent event, not quite regular enough to pinpoint. That’s meaning number four, and today it is still the main one.
But meaning is a slippery substance, and I know of a half dozen songs that use “blue Moon” as a symbol of sadness and loneliness. The poor crooner’s Moon often turns to gold when he gets his love at the end of the song. That’s meaning number five: check your old Elvis Presley or Bill Monroe records for more information.
And did I mention a slinky blue liquid in a cocktail glass, one that requires curaçao, gin, and perhaps a twist of lemon? That’s number six.