August 2012 is a month with two full moons. A Blue Moon is defined as 2 full moons in the same calendar month. Since the first full moon was August 1, the second full moon will be August 31 this month. The time between one full moon and the next is almost the length of a calendar month. So the only time one month can have 2 full moons is when the first full moon happens in the first day of the month. Since this happens every 2-3 years, then the Blue Moons occur that often as well. Thanks to Tom Walden for the information
