Point of information: The phrase "once in a blue moon" should convey something that happens not that often, but also often enough that it's not ultra-rare, like a blue moon, which is most commonly defined as the second full moon to fall in a calendar month. We're having our first blue moon since 2012 tonight, and the next one won't be until January 2018, so all across the internet people are defining the above idiom for anyone left on earth who doesn't know — even though the actual etymology is a little more complicated.

And no, the moon won't be blue. As ABC News, KRON 4, and The Guardian all tell us, the moon only ever takes on a visibly blueish tinge when a volcanic eruption or large forest fire has sent ash into the atmosphere.

So, the phrase "once in a blue moon" can be a misnomer when used simply to mean "very rarely," as it often is, because blue moons as defined above do occur about every 32 months — with the moon's orbit lasting 29.5 days and months being 30-31 days long, this stands to reason.

But here's where the history of the idiom gets tricky: Defining "blue moon" as the second moon in a calendar month appears to date back to 1946 when amateur astronomer James Hugh Pruett defined it as such in an issue of Sky & Telescope magazine. Prior to that, there was a different definition altogether, traceable to the Maine Farmers' Almanac sometime after 1800, that also relates to the discrepancy in the lunar cycle and calendar year that allows for 13 full moons in a year every couple of years. The Almanac defined a blue moon as the third full moon in a season in which there are four — and this was not to be confused with the Native American-derived names for the monthly full moons such as the Pink Moon (April), the Buck Moon (July), and the Harvest Moon (October).

The first use of the term "blue moon" to refer something very rare actually dates back much further than that, to 1528 according to the Morris Dictionary of Word and Phrase Origins. And that meaning could, indeed, refer to seeing a moon that appears blue which is as rare as major volcanic eruptions are.

And, if you put any stock in astrology, you should know that this blue moon is in Aquarius, and it's "unprecedented" for other reasons, according to Elephant Journal.

The energies of this moon are only being magnified by Venus turning retrograde on the 25th, which is just one of seven planets slowing and turning retrograde the week prior to this lunar event.

This cosmic event is unprecedented — it’s truly a month of transitions.

Because of Venus, the planet of love, going retrograde a week prior to this moon, there will be a heavy connection to romantic relationships. This isn’t about just any sort of love though — it’s about the kind of love that comes around only once in a blue moon.

I hope everyone falls in love tonight. The end.