Moon Phases: 'Blue Moon' To Return in August [PHOTOS]
The next Blue Moon can be a second of two full moons of a calendar month. Blue Moons can be third of four full moons a season.
According to Earth Sky, there are many definitions for the term "Blue Moon." Blue Moon usually refers to the second of two full moons in a single calendar month, but it may also be the third or fourth full moon in a single season. A season is defined as the time period between a solstice and an equinox, or vice versa.
The next Blue Moon is scheduled for August 20-21, 2013. The Blue Moon will be seasonal, meaning it's the third of four full moons to take place in a season. In this case, the June 2013 solstice and September equinox. The last Blue Moon by this definition happened in 2010.
The term "Blue Moon" has little to do with the moon's actual color. A tinge of blue may occur in particular atmospheric conditions, such as volcanic eruptions and large fires, when particles are abundant in the atmosphere.
Each month features one full moon (except for February). Click here to see photos of full Blue Moons.