The moving Moon went up the sky,
And nowhere did abide;
Softly she was going up
And a star or two beside - -
From 'The Rime of the Ancient Mariner' by Samuel Taylor Coleridge (1772 – 1834)
The expression 'Once in a Blue Moon' means 'infrequently' or 'rarely' and originally referred to a second full moon in the same calendar month. December 2009 is a Blue Moon month so we can anticipate another full moon on New Year's Eve to shepherd out the old year and welcome in the new.Theoretically, since the moon is full every 29½ days, all months apart from February could experience a Blue Moon but they occur on average only every 33 months. The next Blue Moon after this month's will not be seen until August 2012. A newer definition of Blue Moon describes it as the third of four full moons in a season. I prefer the first characterisation since the seasons, in UK at least, are not always clearly delineated. The December full moon is called the Moon Before Yule, Long Night Moon, Christmas Moon or, more prosaically, the Cold Moon. Last night's full moon, though not the Blue Moon, appeared to have a bluish tinge as it shone through misty clouds.
Perhaps you will have the words and tune of Rodgers' and Hart's song running through your head when you see the words 'Blue Moon' . . .
you saw me standing alone
without a dream in my heart
without a love on my own.
You can listen to Julie London singing it here