Blue Moon

Generally, a month only has 1 Full moon. However, once every couple of years, a month will have 2 Full moons. This occurrence is called a "Blue Moon". This usage results from a misinterpretation of the traditional definition of blue moon in the March 1946 issue of Sky and Telescope.

A blue moon occurs only every two or three years, and the term blue moon is used colloquially to mean a rare event, as in the phrase "once in a blue moon".

The apparent colour of the moon, at any time of the year, can be affected by atmospheric circumstances. Volcanic eruptions and exceptionally large fires can leave particles in the atmosphere which give the sky, and thus the Moon, a tinge of blue (or other colours).

Read more about Blue Moon:  Origin, Early English and Christian Usage, Maine Farmers' Almanac Blue Moons, Visibly Blue Moon, Blue Moons Between 2009 and 2021, Popular Culture

Famous quotes containing the words blue and/or moon:

    Mozart has the classic purity of light and the blue ocean; Beethoven the romantic grandeur which belongs to the storms of air and sea, and while the soul of Mozart seems to dwell on the ethereal peaks of Olympus, that of Beethoven climbs shuddering the storm-beaten sides of a Sinai. Blessed be they both! Each represents a moment of the ideal life, each does us good. Our love is due to both.
    Henri-Frédéric Amiel (1821–1881)

    I got the sun in the morning and the moon at night.
    Irving Berlin (1888–1989)