Once in a blue moon...

and it happened on New Year's Eve
HAPPY 2010
NY Daily News:
There will be a full moon out tonight for New Year's Eve -- and it's blue to boot.

Provided the weather clears, New Yorkers (and anyone else in the Western hemisphere who's looking) will be treated to a view of what's commonly known as a blue moon, defined as the second full moon in a single month, or as the third full moon in a season that has four full moons.
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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.

Blue moons of this sort aren't actually blue in color, though certain natural occurrences, like volcanic eruptions or wildfires, can cause the moon to appear blue, red or orange.

Fortunately for New Year's Eve revelers, full moons are also known for stirring up emotions and sparking wild revelry. So be sure to look up and raise your glass as you ring in 2010.