what does a blue moon mean
Blue moon seen through the Eiffel Tower. A blue moon is an additional full moon that appears in a subdivision of a year: either the third of four full moons in a season, or a second full moon in a month of the common calendar.lue moon seen through the Eiffel Tower. A blue moon is an additional full moon that appears in a subdivision of a year: either the third of four full moons in a season, or a second full moon in a month of the common calendar.