Roughly every twenty nine and a half days, a full moon occurs when sunlight fully illuminates Earth facing side of the Moon. Phases of the Moon are a matter of perspective, perceptible refracted light in relation to lunar orbit define phases of the Moon. We see a full moon when it orbits on the exact opposite side of Earth from the Sun.
Depending on where you live the first full northern hemisphere spring, southern hemisphere fall moon falls on April 11, 2017. Native American tribes dubbed spring’s first full moon the Pink Moon, named for wild pink ground phlox, the first bloom of spring. Also known as the Flower, Sprouting Grass, Egg and Fish Moon, spring’s first full Pink Moon is believed to have originated on America’s east coast with native Algonquin tribes.
If you happen to fall under pink moonlight, ponder long ago and once upon a time. Gaze into the night, embrace prickles of instinctive wisdom with reverence for people who once called spring’s first full moon pink.Next, listen to Nick Drake’s Pink Moon….
Tonight’s’ full moon sets the stage for a Blue Moon on July 31st. “Blue Moon” refers to a second full moon in a calendar month. Our moon follows a 19 year loop called the Metonic Cycle – every 19 years phases of the moon recur on or near the same calendar date. Nineteen years has 228 months with 235 full moons, meaning 7 of those 228 months have a blue moon. Sometimes February’s short number of days produces 8 blue moons in a Metonic Cycle (February 2018 won’t have a full moon, pushing the extra moon to another calendar month)
Popular use of the term is credited to a 1946 issue of Sky and Telescope magazine. Author James Hugh Pruett penned an article “Once In A Blue Moon”, Pruett inadvertently screwed up finer details when referencing the 1937 Maine Farmer’s Almanac – nevertheless “once in a blue moon” was born.
The Maine Farmers Almanac described blue moons as an extra full moon in a “season”. Each season – spring, summer, fall, winter typically has 3 full moons, when a 4th happens, the 3rd moon of that season becomes the blue moon. By this rule the next one falls on May 21, 2016. Although two distinctly different definitions exist, most people subscribe to the monthly club.
It’s possible to have 2 blue moons in a calendar year, the next time is January and March of 2018, followed by January and March 2037. Sometimes a rare year has both monthly (2 full moons in a month) and seasonal (3rd full moon of 4 in a season) – don’t hold your breath, it will be 2048 before the monthly in January, seasonal in August.