Blue Moon, Lunacy, the Dark Side of the Moon, and More

"Tonight's Blue Moon: All a Big Mistake"
Space.com (December 31, 2009)

"Revelers can ring in the new year with a cosmic flourish tonight, celebrating the first New Year's Eve blue moon since 1990.

"In truth, tonight's full moon won't be much different than any other full moon. In fact the term "blue moon" as it's used today originates from a writer's mistake.

" 'The "blue moon" is a creature of folklore,' says Philip Hiscock, a folklorist at the Memorial University of Newfoundland. 'It's the second full moon in a calendar month.'

"If there's been a recent volcanic eruption that poured significant ash into the upper atmosphere, it is possible for the moon to take on a blue tint. That's not expected tonight...."

There's more: an explanation of how "blue moon" came to mean what it does now; a discussion of the "dark side" of the moon; a word or two about the moon and behavior (academically speaking, there isn't any); whether the moon is moving away from us (it is); and more. One or two points, I think, are more a matter of quibbling with language - but it's a fun read.