August 21, 2013 Full moon, another blue moon.

Here's the full moon last night which is the 7th lunar month full moon this year as seen from Southeast Michigan. 

As this is the 3rd full moon of a 4 full moon summer season, by one definition the full moon last night is also a blue moon.  I was a little puzzled at first because this one was the only full moon of the month, how can that be a blue moon?  Well what I didn't know is that there are different definitions of blue moon. 

Anyway "once in a blue moon", we just had another one, so it goes!