If anything unusual happens to you Friday, you'll be right to say it was "once in a blue moon."
The July 31 appearance of the month's second full moon will be the first such occurrence in the Americas since August 2012. Every month has a full moon, but because the lunar cycle and the calendar year aren't perfectly synched, about every three years we wind up with two in the same calendar month.
-Us Open of Surfing:
Watch live here: http://bit.ly/USOpen_Live