The Dawning of the Age of Aquarius

A few months back I had the odd problem of needing to prepare something to say about astrology (in a non-astronomical gathering). I realized I didn’t actually know very much about it, beyond my sign (Virgo) and the one-paragraph-fits-all style horoscopes you see in the newspaper.

Oh, and I knew one other thing about astrology: your “birth sign” isn’t actually the constellation the sun was in when you were born, because of the precession of the Earth’s spin. The least I could do was to find out my real - my astronomical - birth sign.

So I fired up XEphem (any planetarium program works) and ran the date back to find out what the sky really looked like when I was born.

Turns out the Sun was in Leo, not Virgo. The constellations have shifted due to precession, a small wobble in the Earth’s orbit, in the couple of thousand years since the zodiac was invented. So I’m an astrological Virgo but an astronomical Leo.

Then I checked the positions of the planets. The moon was new. Saturn was in Aquarius and Neptune was in Libra. Jupiter was in Taurus. When I told Dave, he said that means I have a lot of bull.

Venus and Mars were straddling the border between Cancer and Gemini, about as close to each other as the Sun and Moon, less than five degrees apart. Hey, maybe that’s why I like all these traditionally male pursuits like astronomy and physics! Yeah, Venus and Mars together, that explains it, sure.

Since the Moon was new, it was quite close to the Sun, only about five degrees away. Also nearby in Leo were Mercury, Uranus, and Pluto - the innermost and outermost planets. Quite a syzygy!

As long as I was researching astrology, I thought I should look into that “Age of Aquarius” business. I mean, I probably heard the song a bazillion times growing up. So what’s the deal? Are we in the Age of Aquarius yet - did it start in the sixties, or what? If not, what age are we in?

Well, it turns out it’s a lot more complicated than that. It’s so complicated ... that nobody has a clue when the Age of Aquarius starts!

“Ages” in astrology go back to precession again. It takes 25,800 for a complete precession cycle. During this time, the Earth’s axes, where you point your equatorial mount (currently pointing at Polaris to the north) will make a complete circle and come back to where it started. The location of the equinoxes - the points at which Earth’s equator intersects the ecliptic - will also make a complete cycle.

There are two equinoxes: vernal (spring, currently in Pisces) and autumnal (fall, currently in Virgo). An astrological age represents the time it takes for the vernal equinox to move from one sign to another. It used to be in Aries, now it’s in Pisces, and the Age of Aquarius starts when it moves into the sign of Aquarius.

But note that “sign” and “constellation” aren’t exactly the same: constellations aren’t all the same size, but astrological signs divide the year into twelve equal parts.

And therein lies the problem. See, it’s easy to tell when the vernal equinox moves into the constellation of Aquarius. But the Age of Aquarius doesn’t start until it moves into the sign of Aquarius. And where is that? Well, it’s calculated as a fixed distance from the beginning of Aries. And where is that? Well, it’s where the vernal equinox was when astrology began, when the astrological signs corresponded with the zodiacal constellations in the sky.

And when was that? Well, it turns out astrologers don’t agree. There are several different schools of thought, and depending on which one you choose, the Age of Aquarius might start in 2600, 2595, 2654, 2638, 2150, or 2062.

Wait - not in the 1960s? But what about the song?

It turns out the song was referring to the “dawning” of the age, which doesn’t require that the vernal equinox actually be in Aquarius, only that it be near enough to be influenced by it.

And there you have it. (Where? What? Um, never mind, I’m not sure either.) Seems suitable fodder for an April 1 column.

Oh, in case you wanted to know about actual planets to look at this month: Saturn is in Leo and is visible all night. Mars is still visible in the western sky all evening, nestled between the two Gemini twins. Jupiter, in Sagittarius, rises in the wee hours of the morning. Pluto is also in Sagittarius, a couple of hours ahead of Jupiter. The Sun, Venus and Mercury are all nestled together in Pisces, with Uranus just over the border into Aquarius and Neptune a bit over an hour ahead in Capricornus.