What Is a blue moon?

Answer 1

The term Blue Moon has at least four related meanings. One is a common metaphorical phrase for a rare event that really has little to do with the moon itself. Another is a description of the apparent color of the moon, which is frequently yellowish and rarely bluish. Full moons are given names in folklore, and two definitions of blue moon are a name for a rare full moon that does not have a folk name. One modern blue moon definition is for a second, extra full moon that occurs in a calendar month. The older definition of blue moon is for an extra full moon that occurs in a quarter of the year, which would normally have three full moons, but sometimes has four. Oddly, it is the third full moon in a season that has four which is counted as the "extra" full moon and named blue moon.

Answer 2

A blue moon is the second full moon in the same month. For example, if there was a full moon on December 1, and then a full moon on December 29, the second full moon in hte month would be considered a blue moon. It happens but not that often. That's why you would hear the expression "Once in a blue moon."

Answer 3

http://skytonight.com/observing/objects/moon/3304131.html?page=1&c=y

Recent decades have seen widespread popular embrace of the idea that when a calendar month contains two full Moons, the second one is called a "Blue Moon." The unusual pattern of lunar phases in early 1999 — two full Moons each in January and March, and none at all in February — triggered a groundswell of public interest. Countless newspapers and radio and TV stations ran stories about Blue Moons.

...more than 40 editions of the Maine Farmers' Almanac from the period 1819 to 1962. These refer to more than a dozen Blue Moons, and not one of them is the second full Moon in a month. What's going on here?

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During the period 1932 to 1957, under the editorship of Henry Porter Trefethen (1887-1957), the Maine Farmers' Almanac consistently listed Blue Moons derived from the convoluted seasonal rule just described. So where did the modern convention — that a Blue Moon is the second full Moon in a calendar month — come from? Sky & Telescope has, and is, the answer!

Laurence J. Lafleur (1907-66) of Antioch College, Ohio, discussed Blue Moons in a question-and-answer column in Sky & Telescope, July 1943, page 17, citing the 1937 Maine Farmers' Almanac as his source. It is clear that Lafleur had a copy of the almanac at his side as he wrote, since he quoted word for word the commentary on the August 1937 calendar page. This commentary notes that the Moon occasionally "comes full thirteen times in a year," but Lafleur did not judge whether this referred to a tropical year or a calendar year. More important, he did not mention the specific dates of any Blue Moons and never said anything about two full Moons in one calendar month.



http://skytonight.com/observing/objects/moon/3305141.html


"According to old folklore," some people say, the second full Moon in a calendar month is called a "blue Moon." They go on to explain that this is the origin of the expression "once in a blue Moon." But it isn't true! The term "blue Moon" has been around a long time, well over 400 years, but its calendrical meaning has become widespread only in the last 20 years.

Answer 4

A 'blue moon' is when you have a second full moon in a calender month. It doesn't happen often, so that's where the expression 'once in a blue moon' came from.

Answer 5

A "blue moon" is the second of two full moons that occur in a single month. It occurs regularly but infrequently. Hence, the term is sometimes used to indicate a time frame for an event that seldom happens...

Answer 6

a blue moon is the second full moon that occurs within the same calandar month.

Answer 7

It symbolizes ''love''. I would like to take you as my blue moon

Answer 8

Second full moon in a calendar month.