The Blue Moon
The term "blue moon" traditionally referred to cases where a three month season had four full moons (instead of the usual three). A season is not defined as a calendar quarter in a year beginning on January 1 but as one quarter of a year measured from solstice to solstice. The third moon in the season is deemed "blue" instead of the fourth by almanacs because the full moons occurring closest to solstices and equinoxes already have traditional names.
A mistaken definition, that the second full moon in a calendar month is known as a blue moon, became common in parts of the U.S. during the second half of the twentieth century due to a misinterpretation of the Maine Farmers' Almanac in the March 1946 Sky & Telescope magazine; this was corrected in 1999.
Since there are on the average 12.37 full moons in a year, a "blue moon" must occur on the average every 2.7 years (7 times in the 19 years of the Metonic cycle), by either definition.
Read more about this topic: Full Moon
Famous quotes containing the words blue and/or moon:
“... wounding God with his blue face,
his tyranny, his absolute kingdom,
with my aphrodisiac.”
—Anne Sexton (1928–1974)
“When we choose to be parents, we accept another human being as part of ourselves, and a large part of our emotional selves will stay with that person as long as we live. From that time on, there will be another person on this earth whose orbit around us will affect us as surely as the moon affects the tides, and affect us in some ways more deeply than anyone else can. Our children are extensions of ourselves in ways our parents are not, nor our brothers and sisters, nor our spouses.”
—Fred Rogers (20th century)