On August 31, the blue moon will rise in the skies and many are wondering what a blue moon is exactly. First off, it isn't blue.
A blue moon isn't too much more than a regular full moon. What makes it unique is that it is the second full moon in a month. The full moon on August 31 is the second moon this month. The first occurred on August 1. It takes the moon 29.5 days to fully orbit the earth, which is why it is rare for two full moons to occur in one month as not even every month has over 29 days.
A blue moon is typically not blue at all, but on rare occasions it may be tinted blue as any full moon can be.
According to NASA.gov, "Squeezing a second full Moon into a calendar month doesn't change the physical properties of the Moon itself, so its color remains the same... However, be aware on rare occasions it can happen."
A moon can turn blue when there is a volcanic eruption on earth or a large forest fire. The smoke from the eruption or fire rises up, making the moon look hazy and giving it a blue tint.
So if a blue moon has nothing to do with color, what's up with the name?
The name was started as a mistake.
Philip Hiscock, a folklore expert at Memorial University of Newfoundland, found that the term has been around for over 400 years, but it became popular in the 1980's.
Hiscock discovered that the term was used to describe things that were absurd. This led to its second meaning of "never." Much like the term, "when pigs fly," people would say "when the moon is blue."
Amateur astronomer, James Hugh Pruett wrote an article in Sky & Telescope magazine in 1946 in which he tried to explain the term. His definition came from an incorrect interpretation of a complicated definition in the Maine Farmers' Almanac, which used "blue moon" to mean to the third full moon in a season that contained four of them (rather than the usual three). Pruett seems to be the one who came up with the two full moons in a month definition.
This error was then popularized by a radio program broadcast in January 1980 called "Star Date." The term was then publicized in "The Kids' World Almanac of Records and Facts" in 1985 and it became a trivia question in the 1986 version of Trivial Pursuit.
In 1999, Hiscock and Texas astronomer Donald W. Olson helped the Sky and Telescope magazine realize and admit to the mistake. The mistake led to the common definition of a blue moon being the second full moon in a month.
A blue moon is significant because it occurs roughly once every 2.7 years, hence the term, "once in a blue moon." The last time this occurred was on New Year's Eve in 2009 and the next one won't occur until July 31, 2015.
For more information and to watch the blue moon online, click here.
This article is copyrighted by Travelers Today, the travel news leader
