Wednesday, December 30, 2009

It's going to be a Blue Moon New Year's Eve!

Fun facts to know and tell about the New Year's Eve moon from National Geographic:

For the first time in almost 20 years, a bright "blue moon" will grace New Year's Eve celebrations worldwide.

If the skies are clear, revelers looking up at midnight will get an eyeful of the second full moon of the month—commonly called a blue moon. The last time a blue moon appeared on New Year's Eve was in 1990, and it won't happen again until 2028.


RonF said...

You might be interested to know that the definition of "blue moon" that you are using here is relatively new and is due to a mistake by a magazine editor.

Every moon has a name. You've heard the song title "Shine on Harvest Moon"? Well, that name for that full moon isn't one made up by the song writer. There are names for 12 of the full moons you can count on seeing during the year. But the year is based on the ecclesiastical year from one Vernal Equinox (when we cross from winter to spring, generally on March 21st) to another. Based on that, the last full moon of the year, in Lent, is called the Lenten Moon. The first full moon of the year, after Easter, is called the Egg Moon. All the others (including the Harvest Moon) have names as well.

But due to the fact that the Moon's orbit is only 29 days and change long, 7 times in a 19 year cycle there are 13 full moons in a year. In that case, the rule USED to be that the 3rd full moon of a given season that had 4 in it was termed "Blue Moon". That was the rule for centuries until Sky and Telescope (a favorite magazine of mine) misquoted the rule in about 1950, and told people that it was the 2nd full moon in a month instead of the 3rd of 4 full moons in a season. Nobody caught the error, and in 1980 it passed into popular use after the error was repeated on a radio show run by people associated with the magazine. So although the incorrect usage is only about 30 years old, it has supplanted the previous centuries-old rule and that's what people use now. It's all explained in this article in Sky and Telescope, the magazine that caused the problem in the first place.


Actually, that was all in the rest of the National Geographic article as linked. Interesting stuff!

Caminante said...

Yup and for those of us who have Concept2 ergometers (rowing machines), they have a blue moon or whatever you want to call it row tomorrow (do two sets of 5K) for a certificate (oh wow but it is an incentive regardless). The thought of doing this in a garage where the temperature is 15 is not exactly thrilling so I may hie it over to the rectory a bit earlier on in the day so I can do it in my 60-degree study.