[Adapted from Farmers’ Almanac]
For more than half a century, whenever two full Moons appeared in a single month (which happens on average every 2 1/2 to 3 years), the second has been christened a “Blue Moon.” In our lexicon, we describe an unusual event as happening “Once in a Blue Moon.” This expression was first noted back in 1821 (although there are earlier references dating back to the 16th Century) and refers to occurrences that are uncommon, though not truly rare.
Why “Blue” Moon? For the longest time nobody knew exactly why the second full Moon of a calendar month was designated as a Blue Moon. One explanation connects it with the word “belewe” from the Old English, meaning “to betray.” Perhaps, then, the Moon was “belewe” because it betrayed the usual perception of one full Moon per month. However, in the March 1999 issue of Sky & Telescope magazine, author Phillip Hiscock revealed one somewhat confusing origin of this term. It seems that the modern custom of naming the second full Moon of a month “blue,” came from an article published in the March 1946 Sky & Telescope magazine. The article was “Once in a Blue Moon,” written by James Hugh Pruett. In this article, Pruett interpreted what he read in a publication known as the Maine Farmers’ Almanac [no relation to the current Farmers’ Almanac, published in Lewiston, Maine], and declared that a second full Moon in a calendar month is a “Blue Moon.”
However, after reviewing the Maine Farmer’s Almanac, Hiscock found that during the editorship of Henry Porter Trefethen (1932 to 1957), the Maine Farmers’ Almanac made occasional reference to a Blue Moon, but derived it from a completely different (and rather convoluted) seasonal rule. As simply as can be described, according to Trefethen’s almanac, there are normally three full Moons for each season of the year. But when a particular season ends up containing four full Moons, then the third of that season is called a Blue Moon! To make matters more confusing, the beginning of the seasons listed in Trefethen’s almanac were fixed. In other words, the current use of “Blue Moon” to mean the second full Moon in a month can be traced to a 55-year-old mistake in Sky & Telescope magazine.
Regardless of whether it’s a true Blue Moon or not, Thursday, December 31, 2009 is a “once in a Blue Moon” opportunity to say goodbye to 2009 and welcome in 2010 in style, while helping the AIDS Council mark the end of its 25th year of service. To reserve your place at the Once in a Blue Moon Gala, click HERE, or call 518.434.4686 Ext. 2428.
