Where does the Phrase "once in a blue moon come from"?

Question

Where does the Phrase "once in a blue moon come from"

Answer 1

"Once in a blue moon" means *exceedingly* rare (in fact, something you might NEVER see!)... much rare than the "second full moon in a month" explanation suggests.

In fact. . . sorry to all those who have accepted the notion, but the "second full moon in a month" explanation is incorrect in two respects.

First, the astronomical use of the expression "blue moon" is very recent and is NOT the source of the old expression "once in a blue moon" , which appeared in print as early as 1528 -- and seems to have more to do with a LITERAL "blue moon" (a rare occurrence, at best)

Second, the "second full moon" explanation was itself based on a misunderstanding of the astronomical use of the term!

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The Astronomical Mistake

This "second full moon" explanation, popularized by the board game "Trivial Pursuit" is actually based on a mistake in a 1946 article in Sky & Telescope magazine.

In 1999 the magazine printed two articles on the subject by way of retraction

A) explaining the REAL meaning of the astronomical expression (which is somewhat more complicated than the catchy "second full moon" idea),
"What's a Blue Moon?"
explains the correct astronomical usge -- when a season contained four full moons, the third was known as a "blue moon" -- and how the 1946 mistake came about
http://skytonight.com/observing/objects/moon/3304131.html?page=1&c=y

and
B) tracing just how the mistake was made and has spread into popular lore (via radio, Trivial Pursuit and newspaper articles)
"Once in a Blue Moon:Fact and fantasy about blue Moons" by Philip Hiscock
(opening snip)
"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."
http://skytonight.com/observing/objects/moon/3305141.html

Compare
http://www.wilsonsalmanac.com/bluemoon.html

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The REAL Origins

But all the astronomical uses (even the correct one!) are very recent, and have nothing to do with the origins of the expression "Once in a blue moon"

An sample explanation of the meaning
E. Cobham Brewer 1810–1897. Dictionary of Phrase and Fable. 1898.
Blue Moon: Once in a blue moon. Very rarely indeed.
On December 10th, 1883, we had a “blue moon.” The winter was unusually mild.
http://www.bartleby.com/81/2105.html

Here is an explanation of just what the older "blue moon" of the expresion was:

"Once in a Blue Moon" is a phrase that refers to something that in all likelihood will never happen at all or only far off in the future. . . . The expression itself derives from the extremely rare, actually blue-tinged Moon caused by atmospheric layers of forest-fire smoke or volcanic dust at just the right height and visual angle, a rare occurrence."
http://www.ipl.org/div/farq/bluemoonFARQ.html

(Also note that the original "blue moon" need not be a FULL moon.)


See also the summary & links at:
http://en.wikipedia.org/wiki/Blue_moon

Answer 2

I give this 10 hugs! ma wrote one the other day that spoke to me on an intuitive level. Deep as if connected I felt her poem. I know this poem and wish I could have come up with the tools you used to deliver it- I love the way you chose the dictionary, calendar, well meaning and future hope. I really don't think some people will ever feel the realization of deeper understanding. This leaves me with remembering the grief that I am truly alone because nothing and no one can at times make it better. My spirituality is the only porthole and even then because I am not perfect, I doubt. I know I've "gone off" from where this lead but lol that is me. BTW- Love the last line so very much.

Answer 3

Well a blue moon is a second full moon in a month. Getting a blue moon is pretty rare, so Once in a Blue Moon means not often. :) hope that helped

Answer 4

A blue moon is rare hence the phrase meaning not often.

Answer 5

A blue moon is when there are two full moons in a month (months are mostly longer than lunar months), which only happens a couple of times a year - so once is a blue moon is pretty infrequently.

Answer 6

A blue moon is a genuine phenominon, but it occurs very rarely

The key to a blue moon is having in the air lots of particles slightly wider than the wavelength of red light (0.7 micron)--and no other sizes present. This is rare, but volcanoes sometimes spit out such clouds, as do forest fires:

Answer 7

two full moons in a single month the second full moon is called a blue mon

Answer 8

the moon looks blue occasionally - very rare, hence the saying

Answer 9

i no what it means but i dont no where it came from sorry =D