Did you see it? That rare conjunction of a supermoon, a blue moon and a full lunar eclipse, all in the night sky over Riverbank this past week?
Wednesday, Jan. 31, was the day, or night, actually, when local astronomers, both hobby and professional, were able to look up into the darkness and observe the lunar shenanigans, from moon rise until sunrise the next day.
First defined in 1979, a supermoon occurs when the moon’s elliptical approach is closest to the earth, making the moon the largest it can be in the night sky.
A supermoon occurs approximately every 14 months. The next super moons will fall in 2019, on Jan. 21, Feb. 19, and March 21.
During the last such cycle, on Nov. 14, 2016, viewers ‘saw the most impressive supermoon since Jan. 26, 1948,’ according to scientific reports.
Originally intended to imply ‘never,’ the term “Blue Moon” was proven to actually exist when the dust from a volcanic eruption in the 1880s caused the full moon to actually appear bluish.
Since astronomer James Pruett’s article in the 1946 edition of the Sky & Telescope Magazine, the definition of Blue Moon has come to mean ‘rarely,’ since there are usually two full moons in a month about every 14 months, and is now considered simply a ‘rare’ occurrence.
And since they come about 29.5 days apart, one can never happen in February.