Have you ever heard the phrase "once in a blue moon" and wondered what it means? It's a common saying that refers to a rare event or occurrence. But where did this expression come from and how often does a blue moon actually happen? Let's find out.
What Is A Blue Moon?
A blue moon does not actually refer to the color of the moon. Instead, it is the rare occurrence of a second full moon in a calendar month. Normally, a full moon occurs once every 29.5 days, so it is rare for two to happen in the same month. This event happens roughly once every 2.7 years, which is why it is considered a rare occurrence.
The Origin Of The Phrase
The phrase "once in a blue moon" has been around since at least the 16th century, but it was not originally associated with the phenomenon of two full moons in a month. Instead, it was used to describe something that was impossible or absurd, much like saying "when pigs fly" today. The association with the blue moon event did not come until the 1940s.
The Different Types Of Blue Moons
There are actually two different types of blue moons. The first is the aforementioned occurrence of two full moons in a calendar month. The second type is a seasonal blue moon, which is the third full moon in a season that has four full moons. This happens roughly once every 2.7 years as well.
The Color Of The Blue Moon
Despite the name, a blue moon is not actually blue in color. However, under certain atmospheric conditions, the moon can appear bluish in color. This usually happens after a volcanic eruption or a large wildfire, when smoke and ash can scatter light in the atmosphere and cause the moon to appear blue.
The Super Blue Blood Moon
In 2018, a rare celestial event occurred that combined a blue moon, a supermoon, and a total lunar eclipse. This event was called the super blue blood moon and it had not happened in over 150 years. During this event, the moon appeared larger and brighter than usual, and it had a reddish hue during the eclipse.
The Cultural Significance Of The Blue Moon
The blue moon has been referenced in various forms of popular culture, including music, literature, and film. The song "Blue Moon" by Richard Rodgers and Lorenz Hart is one of the most famous examples. The phrase has also been used in movies such as "Grease" and "The Smurfs."
When Is The Next Blue Moon?
The next blue moon will occur on August 31, 2023. This will be the second full moon in the month of August. So mark your calendars now!
Conclusion
A blue moon is a rare and interesting phenomenon that has captured the attention of people for centuries. Whether you believe in the cultural significance of the event or simply enjoy the beauty of a full moon, the blue moon is something worth experiencing at least once in your lifetime.