The term "blue moon" is used when something very rare happens, the most common usage of this term is "Once in a blue moon".
There are 2 uses of the term 'Blue Moon' - Because the lunar cycle is 28 days and the year has 365 days it works out that there are 13 new moons in a year. The year is divided into 4 seasons - Spring, Summer, Autumn and Winter, each of which would have 3 new moons (which are referred to as the Early Spring Moon, Mid-Spring Moon, Late Spring Moon and so on for the other 3 seasons) and wherever the extra 13th new moon falls it is given the name Blue Moon and this term is used to describe the 3rd new moon out of the 4 in the season. It would look exactly the same as the other 12. The other use of the term Blue Moon is when certain atmospheric conditions, usually smoke at high altitude, gives the Moon the appearance of a slightly blue tint.
The last one was December 31st 1990. The next one is December 31st, 2009.
The phrase "once in a blue moon" refers to something that happens very rarely. A blue moon is the term used for the second full moon occurring within a single calendar month, which is an uncommon event. The idiom emphasizes the infrequency of an occurrence, highlighting its uniqueness or rarity in everyday life.
A blue moon is the term used when there are two full moons within the same calendar month. This occurs about every 2.7 years on average.
The term "lunar" is used for things relating to the moon.
When a single month has two full moons, the second full moon is called a Blue Moon. It happens every 2-3 years. Originally, the Maine Farmer's Almanac defined a "blue moon" as the 13th moon in a tropical year(from winter solstice to winter solstice). Normally, each season would consist of 3 moons. In a season of 4 moons, the third would be considered blue. Blue ink was used to record this event in the almanac. As a reference to the event, though, the idiom "once in a blue moon" means rarely. There is no set amount of time.
A "blue moon" traditionally refers to the second full moon that occurs within a single calendar month, which is a rare event. This phenomenon happens approximately every two to three years. The term is often used colloquially to signify something that is uncommon or infrequent. Additionally, in older definitions, a blue moon could also refer to the third full moon in a season that has four full moons.
Waxing. This term is used to describe the phase of the moon when it appears to be growing larger in the sky as it transitions from a new moon to a full moon.
It would seem to come from an olde English word "belewe" meaning betrayer.This was used by the early clergy to describe a moon which was too early for the lent moon. This moon was called the betrayer moon or belewe moon.
The term used to describe the decrease in the visible portion of the moon is "waning." This occurs as the moon transitions from a full moon to a new moon phase.
The term used to describe a large natural satellite of any planet is a "moon."
The term "blue moon" traditionally refers to the second full moon in a calendar month with two full moons, a definition popularized in the 1980s. However, its origins date back to the 19th century, where it was originally used to denote the third full moon in a season that has four full moons. The phrase has also appeared in folklore and literature, often symbolizing rarity or something unusual. Today, "once in a blue moon" signifies an event that occurs infrequently.