Tonight is ‘once in a blue moon’

Published 7:15 pm Wednesday, December 30, 2009

If you’ve ever put off something until the next blue moon, thinking it is a long, long time from now, you only have a few more hours remaining.

Thursday evening will mark the first blue moon since May 31, 2007, and is the first time such an occurrence has happened on New Year’s Eve since Dec. 31, 1990.

The term “blue moon” has nothing to do with the color of tonight’s full moon, but rather the fact it is the second full moon to occur in December. Since a full moon occurs every 29.5 days, having two full moons happens infrequently, but not as infrequently as the old saying “once in a blue moon” might suggest.

According to an article written by SPACE.com columnist Joe Rao, a blue moon occurs “on average, about every 32 months. And in the year 1999, it occurred twice in a span of just three months.”

Rao also noted the phrase “once in a blue moon” was first noted in 1824 and refers to occurrences that are uncommon “though not truly rare.”

Although the current meaning of the phrase carries with it the “rare” definition, it is much argued that it was not the true meaning.

According to the Farmers’ Almanac of Main in 1932, the occurrence of the third full moon in a season where there are four full moons is a blue moon. If that is case, then the last blue moon was May 2008, when the third full moon of the spring season happened.

But the current meaning of the second full moon in a month was adopted later and accepted, since it was much easier for the public to follow.

After Thursday’s full moon, which will actually occur at 2:15 p.m., the next blue moon will be seen in August 2012.

The Web site www.infoplease.com reported there will not be a blue moon during 2011, 2014 or 2017.