(Joseph Gruber/Flickr)When the moon is full on Saturday, Earth’s lunar companion becomes a “blue” moon — in a floral, seasonal way. Popular folklore holds that the second full moon in a given month is a blue moon, but this Saturday’s blue moon has another definition. Chester said this seasonal blue moon — which is the original definition of a blue moon — was first dreamed up by the Maine Farmer’s Almanac in the early 20th century. Thus, May’s usual flower moon becomes a blue flower moon, if we conform to the farmers’ almanacs. “The blue moon is an interesting bit of scientific trivia for those that keep track of these kinds of things,” Chester said.

Source: Washington Post May 17, 2019 16:59 UTC