---------------------- Forwarded by Pam Blythe on 04/02/99 02:49 PM
---------------------------

From:     Tim Poulsen
Date:     03/31/99 08:41:44 AM
Subject:  Blue moon

There are many definitions of what makes a "blue moon." But the one I'm
sure you've heard most is that in a month with two full moons, the second
full moon is the blue moon.

January and March this year both have two full moons. Tonight is the second
full moon of March. Undoubtedly, you've heard many a reporter or weatherman
describe tonight's second full moon as a blue moon.

Well... not so fast! The May issue of Sky &Telescope Magazine details the
history of this modern myth. The term has historically been attributed to
being coined by the Maine Farmers Almanac. The Sky &Tel editors researched
40 issues they were able to find of the Almanac that date as far back as
1819. They found that none of the blue moons listed in the issues were the
second full moon of the month!

It was the conclusion of the article that the definition that fits the data
is one based on the 3rd full moon of a season containing 4 full moons. A
full moon to full moon cycle is roughly a month. So, there should be about
12 per year or three per season. As I said, "roughly." The moon's cycle is
a bit shorter than a month, giving some years an extra full moon. By
folklore, most full moons have names (Harvest moon, Egg moon, etc.) and the
"blue moon" was apparently the name given by the Almanac to the "extra"
one.

So where did the error creep in to our culture? It seems to have originated
in a 53 year old article in Sky & Tel itself. James Hugh Pruett, a frequent
contributer to the magazine, wrote an article that year on the full moons
of the year. He mis-interpreted a historical reference to the Maine Farmers
Almanac and stated "This second in a month, so I interpret it, was called a
Blue Moon." Thereafter, it was repeated many times in Sky & Tel and on
Stardate, a radio program about the sky. The term is now the commonly
quoted definition.

So when is the next blue moon by the "original" definition? February 19th,
2000!!!!

The complete Sky & Tel article is online at
http://www.skypub.com/sights/moonplanets/9905bluemoon.html

By the way, some of the other definitions of blue moon are:

1) An absurdity - way back, people used the term to represent something
that just couldn't happen. Everyone knew the moon wasn't blue, just was we
know that it isn't made of green cheese.

2) Never - Flowing from the first definition, saying something would happen
"when the moon was blue" was the equivalent of saying that it would never
happen.

3) It's actual color - in rare cases, the moon actually looks blue. This is
most often caused by lots of soot in the air from a large volcanic
eruption.

4) Flowing from definition 3, since once in a great while the moon actually
is blue, the phrase "once in a blue moon" came to represent an infrequent
event.

5) Sadness - typically used in songs, the blue moon represents the singer's
depressed or lonely state. (check your old Elvis Presley or Bill Monroe
records for more information)

6) Of course, there's a drink called a blue moon made with curaçao, gin, a
twist of lemon.

That, plus the (now determined to be wrong) second full moon of the month
and the actually true third full moon in a season with four full moons
makes eight definitions for "blue moon."

Tim