I had a headache before I saw this little tidbit of are you fucking kidding me everywhere. So for my itchy brain’s sake, let’s chuck this on the explainer pile.
Today’s Moment of Science… SUPER BLUE MOON, MAN!
Back when humans started counting shit we were, without question, terrible at it. As soon as agriculture was a thing, early civilizations needed to sort out how many appearances the sun made from one cycle of sowing and reaping to the next. This happened a good long time before Copernicus published his little “we’re not the center of the fucking universe” rant, so uh. Mistakes were made, but given that they thought the Sun and Moon just took a meal break at the end of their shift or whatever, it could have been worse.
Many early calendars were based around the lunar cycle, with twelve months each following one revolution of the Moon. Famously, the Egyptian calendar had twelve lunar cycles plus an extra five or six days tacked on at the end of the year to sort shit out. Vestiges of this can still be seen in our modern Gregorian calendar (and plenty of other calendars still used in religious traditions).
Funny thing about a lunar cycle though- it doesn’t last a perfectly even number of Earth days (and a day isn’t always exactly 24 hours so what the fuck do we even know?). It’s… well, a little complicated. It takes 27.3 days to rotate around the Earth, but we see a lunar cycle happening about every 29.5 days. Tide goes in, tide goes out, you can definitely goddamn explain that.
Hokay, here’s the Earth. That is a pretty sweet Earth. Ahem, where was I? If we could look down at the Earth and Moon from above (or bottoms up, you perverts), from that perspective we’d see the Moon make one full trip around us every 27.3 days. However, the way we view our closest celestial neighbor is influenced by our positions relative to the sun. Bit of a massive over-simplification, but since it’s racing around us while we’re hurtling around the sun, it needs a bit of travel time to really nail its light for a full moon. We see one full lunar cycle not in 27.3 days when one revolution around us is complete, but in 29.5 days, when we view the Moon as returning to the same position relative to our solar system’s nuclear engine.
“Ms. Auntie SciBabe, the fuck does any of this have to do with the blue moon?”
Settle down, I was getting there.
Despite what my seventh grade science teacher told us (so much for that private school education, Mom), a blue moon has nothing to do with atmospheric conditions that make our natural satellite appear a bit grumpy.
We’ve tinkered with the length of months (and occasionally years), giving seven months an extra 36 hours(ish) beyond the lunar cycle. And every once in a while, as chance would have it, one of those months begins and ends with a full moon, the second of which is referred to as a blue moon. Depending on who you ask, it can be the third full moon in a season with four full moons, but most people take it to mean the second in a month.
Though it was eventually popularized in the Farmer’s Almanac for this exact phenomenon, where did the curious phrase come from? It seems to have first appeared in a pamphlet attacking the Catholic church:
“O church men are wily foxes (…) If they say the moon is blue, We must believe that it is true.”
Sweet sixteenth century burn. It’s a pretty epic ‘fuck Catholicism’ poem with a few humdingers that should have caught on as insults. Rather though, a ‘blue moon’ came to mean something that was impossible.
Are there conditions that can cause the Moon to appear blue? Yes, but if that’s happening you have more to worry about than the agreed upon term for how many times we’ve seen the Moon this season or month or whatever. A blue hued moon typically comes after a volcano or an incredibly large wildfire. The eruption of Krakatoa allegedly caused the expression change. It became ‘once in a blue moon,’ implying something was a rare event rather than an impossible one.
As for the supermoon? It has a slightly elliptical orbit around us, so it comes a bit closer and appears a bit brighter during some parts of its orbit. But don’t look for anything dramatic- articles claiming it’s 30% brighter are comparing apples to cassowaries. It’s not 30% brighter than last night. It’s about 8% bigger than your average full moon and 14% bigger than a micro-moon, a full moon at the most distant part of its ellipse.
Will you be able to notice when it’s a “supermoon?” Probably not. But when there’s a big bright super blue moon out there, you should take a few minutes (after you sign up for my patreon) and go have a look at it. That said, if you’re looking up at an actual pale blue moon, maybe check if something’s burning.
This has been your Moment of Science, getting laid at least once in a blue moon.
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