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Blue moon

  1. Dec 30, 2009 #1
    This month there are two full moons and the second one is called blue moon. Anyone know why this full moon is called so?
  2. jcsd
  3. Dec 30, 2009 #2
    Blue moons are full moons that aren't timed to the regular monthly pattern. Each calendar year has roughly 11 more days than the lunar year. These days add up until there is an extra full moon that year. It happens every 2-3 years. As for why this was named the Blue moon I'm not too sure.
  4. Dec 30, 2009 #3
    I was reading somewhere that this current definition of what a "blue moon" is fairly new, though the term has been around for much longer.

    I read (if memory serves) that the current definition stems from an attempt by an astronomer writing in an astronomy magazine to summarize and clarify the definition given in the Farmer's Almanac which was, apparently quite obtuse involving the exact date of the beginning of Lent and Easter (or something along those lines).

    EDIT: there is a discussion of this on the wiki page for Blue Moons: http://en.wikipedia.org/wiki/Blue_moon
    Last edited: Dec 30, 2009
  5. Dec 30, 2009 #4
    Just came across this article that gives a few reasons it might be called a blue moon.

    http://www.cnn.com/2009/TECH/space/12/30/blue.moon/index.html" [Broken]
    Last edited by a moderator: May 4, 2017
  6. Dec 30, 2009 #5


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    Here's some lovely music to listen to as you read the blue moon links :smile:.

  7. Dec 30, 2009 #6
    It's moving toward the earth. :rolleyes:
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