http://news.yahoo.com/s/space/20101119/sc_space/thereallystrangestorybehindsundaysbluemoon
The Really Strange Story Behind Sunday's Blue Moon
Buzz up!319 votes ShareretweetEmailPrintJoe Rao
SPACE.com Skywatching Columnist
SPACE.com joe Rao
space.com Skywatching Columnist
space.com – Fri Nov 19, 4:15 pm ET
The full moon of November arrives on Sunday and will bring with it a cosmic addition: It will also be a so-called "blue moon."
"But wait a minute," you might ask. "Isn't a 'blue moon' defined as the second full moon that occurs during a calendar month? Sunday's full moon falls on Nov. 21 and it will be the only full moon in November 2010. So how can it be a 'blue' moon?"
Indeed, November's full moon is blue moon – but only if we follow a rule that's now somewhat obscure.
In fact, the current "two- full moons in one month" rule has superseded an older rule that would allow us to call Sunday's moon "blue." To be clear, the moon does not actually appear a blue color during a blue moon, it has to do with lunar mechanics.
more on the link.
The Really Strange Story Behind Sunday's Blue Moon
Buzz up!319 votes ShareretweetEmailPrintJoe Rao
SPACE.com Skywatching Columnist
SPACE.com joe Rao
space.com Skywatching Columnist
space.com – Fri Nov 19, 4:15 pm ET
The full moon of November arrives on Sunday and will bring with it a cosmic addition: It will also be a so-called "blue moon."
"But wait a minute," you might ask. "Isn't a 'blue moon' defined as the second full moon that occurs during a calendar month? Sunday's full moon falls on Nov. 21 and it will be the only full moon in November 2010. So how can it be a 'blue' moon?"
Indeed, November's full moon is blue moon – but only if we follow a rule that's now somewhat obscure.
In fact, the current "two- full moons in one month" rule has superseded an older rule that would allow us to call Sunday's moon "blue." To be clear, the moon does not actually appear a blue color during a blue moon, it has to do with lunar mechanics.
more on the link.