“Once in a Blue Moon” might sound like a long time, but we’re about to experience one this weekend – and it will be your last-place time to catch one until August 22, 2021.
The full moon on Saturday, May 18, 2019, will be a Blue Moon, according to NASA. There are two main definitions of a Blue Moon, both referring to an additional full moon that appears within a certain window of hour, either a season or a month. Unfortunately, neither involves a sudden coloring modification from our loyal cosmic companion.
This upcoming moon falls under the seasonal Blue Moon definition, which refers to the third full moon in a season that has four full moons.
The other explanation, which is arguably more widely known, designates the second full moon in a calendar month. It’s easy to are of the view that a full moon occurs once a month- as in a “moon-th”- but occasionally a calendar month will fit in two full moons. This is because each cycle of the Moon’s phases lasts about 29.5 dates, yet the following is 30 or 31 dates in a calendar month( except February ). So, every two or three years, there will be 13 full moon , not 12.
While the monthly definition might be more popular, some say it’s actually the result of a publishing screw-up. The definition can be linked back to the March 1946 publication of Sky& Telescope magazine when a reporter misinterpreted the word from an old-time issue of the Maine Farmers’ Almanac. Not recognizing the Moon’s phases in the book were based on a seasonal calendar, he understandably acquired the “extra” moon referred to the months. This explanation was then used as an answer on radio plays and a 1980 s Inconsequential Chase board game, and so the misinterpretation spread.
As mentioned, the Moon won’t literally turn a shade of blue. That said, it’s guessed the saying “Once in a Blue Moon” actually originated in 1883 after the eruption of Krakatoa threw so much dust into the atmosphere the Moon took on a blue hue.
The traditional figure for May’s full moon is sometimes the Flower Moon, used to signify the flowers that bud during this month in the Northern Hemisphere. Traditional identifies of moons are often a mash-up of terms used by ancient cultures, Native american tribes, and European pre-Christian gentiles. Nowadays, they don’t signify all that much, although women do make for some pretty incredible calls. For illustration, in January 2019 we got to witness the “Super Blood Wolf Moon“.