Have you ever heard the expression "Three times in a Blue Moon"?
Of course you haven't. Nobody has.
Nonetheless, as we move into 2010, I've heard or seen three relatively reputable sources define the Blue Moon of New Years Eve, incorrectly!
So what the heck is a blue moon? Clearly I'm not talking about the Marcel's #1 Hit in 1961...
Just to cut to the chase.
First the facts, The full moon rising on New Years Eve 2009 is called a "Blue Moon". The last time a Blue Moon rose on New Years Eve was 1990. The current, common, correct definition of a "blue moon" is a 2nd Full Moon in a month. The more correct definition is when any of the four seasons contain 4 full moons, the 3rd is called a Blue Moon(on average, seasons contain only 3 full moons.)
Obviously there is some history here - that's the really interesting part. Here's the evolution according to Sky and Telescope Magazine. At some point in history, talking about a "Blue Moon" was like talking about green cheese - i.e. impossible. "Once in a Blue Moon" never happened. (I'll have to remember to write an entry about "When Hell freezes over"). However, at some point, people noticed that the Moon is actually occasionally blue - as after Krakatoa erupted in 1883 and the particulates blanketed the planet. So "Once in a Blue Moon" came to mean an extremely rare event. I'm imagining some English barkeep in London muttering to one of his patrons about the grisly chimneysweep in the corner, morose over his ale; "Aye, he pays his bill -Once in a Blue Moon! Har Har"
Jump to America. Apparently American farmers in the east and northeast, adopt the Native American habit of naming the moons to keep in sync with planting cycles and seasons. We see echoes of this today when we talk about a "Hunters Moon" or the "Harvest Moon"(by the way-I have lots to say about moon names-another time). In inevitably, though, when calendars collide, some kind of mayhem ensues. The basis of the synodic month is the lunar cycle which lasts 29.53 days long - somewhere between 29 and 30 days. However, the Gregorian Calendar is divided into months of 30 and 31 (and sometimes 29 or 28) days that roll by inexorablyindependent of what the moon is doing. Somebody has to make an adjustment.
So if your a farmer in America in, say the 18th century. You know you have to pay your rent on land to the landlord on the 1st day of the month. You also know that you need to finish your harvest by the "harvest moon". Because of the mismatch in the lengths of these cycles, every now and then, an extra full moon appears for any given period. The traditional way to deal with it, is to stick it in the middle of the season! According to the Maine Farmers Almanac (which seems to be the ultimate authority on these things), if a season has four full moons, then the third is allowed to be called a "Blue Moon". This allows the famous one "Harvest Moon" to keep its preeminence.
However, this got simplified when Deborah Byrd January, 1980 on the NPR Radio Program Star Date incorrectly defined a "Blue Moon" as the 2nd Full Moon in a month. That's a lot easier to remember and seems to have stuck.
How rare is it? It appears to me that there is a bigger cycle with 7 Blue Moons in 19 years. The last Blue Moon on New Years Eve was 19 years ago in 1990! So not only are we starting a new year and a new decade (don't get me started on this), where also starting a new Blue Moon Cycle. Celebrations are called for!.
There is, of course the vanishingly small chance that I'm wrong too. Given the infinite depth of knowledge of the internet and infallibility of Wikipedia, this seems unlikely, but maybe I'll be fodder for some else's tirade! One can only hope.
Happy New Year to All-I wish you many more Blue Moons.
Of course you haven't. Nobody has.
Nonetheless, as we move into 2010, I've heard or seen three relatively reputable sources define the Blue Moon of New Years Eve, incorrectly!So what the heck is a blue moon? Clearly I'm not talking about the Marcel's #1 Hit in 1961...
Just to cut to the chase.
First the facts, The full moon rising on New Years Eve 2009 is called a "Blue Moon". The last time a Blue Moon rose on New Years Eve was 1990. The current, common, correct definition of a "blue moon" is a 2nd Full Moon in a month. The more correct definition is when any of the four seasons contain 4 full moons, the 3rd is called a Blue Moon(on average, seasons contain only 3 full moons.)
Obviously there is some history here - that's the really interesting part. Here's the evolution according to Sky and Telescope Magazine. At some point in history, talking about a "Blue Moon" was like talking about green cheese - i.e. impossible. "Once in a Blue Moon" never happened. (I'll have to remember to write an entry about "When Hell freezes over"). However, at some point, people noticed that the Moon is actually occasionally blue - as after Krakatoa erupted in 1883 and the particulates blanketed the planet. So "Once in a Blue Moon" came to mean an extremely rare event. I'm imagining some English barkeep in London muttering to one of his patrons about the grisly chimneysweep in the corner, morose over his ale; "Aye, he pays his bill -Once in a Blue Moon! Har Har"
Jump to America. Apparently American farmers in the east and northeast, adopt the Native American habit of naming the moons to keep in sync with planting cycles and seasons. We see echoes of this today when we talk about a "Hunters Moon" or the "Harvest Moon"(by the way-I have lots to say about moon names-another time). In inevitably, though, when calendars collide, some kind of mayhem ensues. The basis of the synodic month is the lunar cycle which lasts 29.53 days long - somewhere between 29 and 30 days. However, the Gregorian Calendar is divided into months of 30 and 31 (and sometimes 29 or 28) days that roll by inexorablyindependent of what the moon is doing. Somebody has to make an adjustment.
So if your a farmer in America in, say the 18th century. You know you have to pay your rent on land to the landlord on the 1st day of the month. You also know that you need to finish your harvest by the "harvest moon". Because of the mismatch in the lengths of these cycles, every now and then, an extra full moon appears for any given period. The traditional way to deal with it, is to stick it in the middle of the season! According to the Maine Farmers Almanac (which seems to be the ultimate authority on these things), if a season has four full moons, then the third is allowed to be called a "Blue Moon". This allows the famous one "Harvest Moon" to keep its preeminence.
However, this got simplified when Deborah Byrd January, 1980 on the NPR Radio Program Star Date incorrectly defined a "Blue Moon" as the 2nd Full Moon in a month. That's a lot easier to remember and seems to have stuck.
How rare is it? It appears to me that there is a bigger cycle with 7 Blue Moons in 19 years. The last Blue Moon on New Years Eve was 19 years ago in 1990! So not only are we starting a new year and a new decade (don't get me started on this), where also starting a new Blue Moon Cycle. Celebrations are called for!.
There is, of course the vanishingly small chance that I'm wrong too. Given the infinite depth of knowledge of the internet and infallibility of Wikipedia, this seems unlikely, but maybe I'll be fodder for some else's tirade! One can only hope.
Happy New Year to All-I wish you many more Blue Moons.
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