Why is this December (2009) a Blue Moon month?  How often is there a Blue Moon Eclipse?

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chicagorilke23 eNotes educator| Certified Educator

The most recent Blue Moon will take place on December 31, 2009. Some countries will experience a double Blue Moon. A Blue Moon is not set on a regular monthly pattern, though they usually occur in months with 31 days. The Blue Moon takes place because each calendar year has extra days. These extra days total 11 and so the additional days add up to where every two to three years there is an extra full/Blue moon. Though a Blue Mon is not technically a full moon, it is categorized as such. For a Blue Moon, long wavelength light shows up as red to viewers. It is spread out from a person's sight range. Short wavelength light is what is recognized by the viewers as being blue. As for an eclipse of a blue moon, I am sure it may happen though I have not found out when it has taken place.

astrosonuthird | Student

A blue moon occures when there is two full moons in a month.


Sometimes it comes. in (2009) december.

ghettoteacher2002 | Student

The moon phases occur on a rather regular cycle.  Because the months have varying number of days, the moon cycles do not follow strictly with the calendar months.  There can be two of any of the moon phases fall within the same month, usually the months with 31 days (simply because the month is longer). 

A blue moon occurs when there are two full moons within the same month. The second full moon is called a blue moon.

It has nothing to do with color.  The colors we see come from the gases in the atmosphere.

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