Blue Moon

A Blue Moon is an extra full moon that appears in a calendar month, typically when two full moons occur within a single month. Since the lunar cycle is about 29.5 days, this phenomenon happens roughly once every two to three years. There are two common definitions: the "seasonal" type, marking the third full moon in a season with four, and the "monthly" type, which is the second full moon in a single month. The term doesn't refer to the moon's color but is a fascinating way to track lunar cycles and calendar patterns.