Leonardo da Vinci’s famous Vitruvian Man, a drawing created circa 1487, with chakras, or energy centers, added. Image via Wikimedia Commons.

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What is the Age of Aquarius, and when does it begin? The Age of Aquarius isn’t part of astronomy. It’s an astrological age, which occurs because of a real motion of Earth known as precession. Precession is what causes the identity of the Pole Star to change over time. The cycle of precession lasts 25,800 years, and there are 12 constellations of the zodiac. So, roughly every 2,150 years, the sun’s location in front of the background stars – at the time of the March, or vernal, equinox – moves in front of a new zodiacal constellation. The Age of Aquarius begins at the point when the sun is no longer in front of the constellation Pisces at the time of the March equinox. At that point – sometimes called the March equinox point, or vernal equinox point – the equinox sun will be in front of the constellation Aquarius.

It seems as if there should be a clearcut answer to these questions. When will the sun be in front of Aquarius at the time of the March equinox? When will the Age of Aquarius begin?

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But there are no clearcut answers. Various interpretations give different answers to this often-asked question.

Constellation Aquarius, as drawn by Hevelius in "Firmamentarium," 1690. Image via Constellations of Words.

Age of Aquarius from astronomical perspective. First of all, we give the answer from an astronomical point of view. The International Astronomical Union (IAU) – which in the 20th century assumed the duty of officially naming and defining all things astronomical – created official constellation boundaries in 1930. From the perspective of astronomy, then, the beginning of the Age of Aquarius is based upon IAU constellation boundaries, which astrologers or New Age practitioners might or might not choose to use in their computations.

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According to the Belgian astronomer and mathematical wizard Jean Meeus (bio here), who does adhere to the IAU’s definitions, the sun at the March equinox passed from being in front of the constellation Aries to being in front of the constellation Pisces in 68 B.C. Looking ahead, again according to Jean Meeus, the March equinox will cross over into the constellation Aquarius in 2597. Once again, these are the astronomical dates, based on IAU constellation boundaries established in 1930.

Other interpretations for the beginning of the Age of Aquarius. The constellations as defined by the IAU are different sizes. Astrologers often like to divide the zodiac into twelve equal sections. For example, the constellation Pisces – as defined by the IAU – spans more than 30 degrees along the ecliptic, or sun’s annual path in front of constellations of the zodiac. Astrologers, though, might disregard the span of the constellation Pisces on the sky’s dome, and instead regard an astrological age as a precise 30 degree shift of the March equinox in front of the backdrop stars.

But even if you equalize the size of the signs of the zodiac, you need to consider when the Age of Pisces started to be able to know when the Age of Aquarius begins. Apparently, there’s no firm consensus among astrologers as to when the Age of Pisces began, either. And thus there is no consensus as to when the Age of Aquarius begins. In The Book of World Horoscopes, Nicholas Campion suggests that approximated dates for entering the Age of Aquarius range from 1447 A.D. to 3597 A.D. Campion also reviewed published material on the subject from astrological sources. He says that most writers claim the Age of Aquarius arrived in the 20th century (29 claims). The 24th century is in second place (12 claims). Campion, by the way, is director of the Sophia Centre and Course Director of the M.A. in Cultural Astronomy and Astrology at the University of Wales, Lampeter. See Campion’s credentials here.

Some astrologers say the Age of Aquarius actually began in 2012. That’s because they believe the star Regulus in the constellation Leo the Lion marked the ancient border between the constellations Leo and Cancer. This star moved to within 30 degrees of the September equinox point in 2012, meaning that Regulus left the sign Leo to enter the sign Virgo in that year. Presuming equal-sized constellations in antiquity, that places the border of the constellations Pisces and Aquarius at 150 degrees west of Regulus, or at the March equinox point. By this reckoning, the Age of Aquarius started in 2012.

But again, although there is firm reckoning by many for the beginning of this astrological age, there is no agreement. Wikipedia lists what various writers have claimed.

To reiterate, we at EarthSky look at the subject from an astronomical perspective. If any knowledgeable astrologers out there would like to show us other ways of determining the Age of Aquarius, please do! We welcome your comments.

Terry MacKinnell responded to our above request, claiming that in ancient Babylon a new zodiacal constellation rising over the eastern horizon before sunrise on the morning of the Northern Hemisphere spring equinox indicated the arrival of a new age. Read more at An Age Old Mistake That Still Haunts Astrologers.

The equinox point moves westward in front of the backdrop stars. Image via Wikimedia Commons.

Definition of terms: March (or spring or vernal) equinox point. This is the point on the imaginary celestial sphere surrounding Earth at which the ecliptic – or path of the sun across our sky – intersects the celestial equator, or line around the sky directly above Earth’s equator. It’s sometimes called the First Point in Aries, because the sun used to be located in front of the constellation Aries at the time of the vernal equinox. For the past 2,000 years, though, the sun has been located in front of the constellation Pisces at the time of this equinox. That’s the significance of the so-called Piscean Age. At some point, the sun at the equinox will be in front of Aquarius. That’s when the Age of Aquarius begins.

How did the Age of Aquarius enter popular culture? The Age of Aquarius in the U.S. is associated with the hippies of the 1960s and ’70s, and now with the New Age movement. In both cases, the arrival of the Aquarian age has been associated with … well, harmony and understanding, sympathy and trust abounding. And that brings us to the 1967 smash-hit musical "Hair," with its opening song Aquarius, by a musical group called the 5th Dimension. The song opened with the lines:

When the moon is in the Seventh House
And Jupiter aligns with Mars
Then peace will guide the planets
And love will steer the stars
This is the dawning of the Age of Aquarius

It’s hard to describe how "Hair," which seems daring even today, affected people when it opened on Broadway in 1968. It subsequently ran for 1,750 performances on Broadway and 1,997 performances in London, with simultaneous productions in cities across the United States and Europe, and with accompanying recordings (the original Broadway cast recording sold three million copies). Almost single-handedly in the late 1960s and early 1970s, this Broadway musical brought the Aquarian Age concept into the popular culture. The video below isn’t the original, but you’ll get the idea.

Bottom line: The Age of Aquarius begins when the March equinox point moves out of the constellation Pisces and into the constellation Aquarius. But there’s no definitive answer as to when that will be.