DETROIT -

August has been deemed Blue Moon Month because it will see not one, but two full moons by its last day.

A blue moon is referred to as being the second of two full moons within any given month, according to some almanacs and calendars. The phrase "once in a blue moon" indicating the rarity of an event, began in 1824.

Blue moons are rare but they can be predicted to happen every three years or so. The name comes from the colors the moon takes on from time to time due to different conditions.

The first full moon is August 2nd the next one is August 31st.