Ancient Skies and Axial Precession
Let us begin this discussion by imagining the night sky. You are far, far out in the country. There are no city lights. You can see all the stars and the swath of the Milky Way. The night sky was extremely important to our ancestors because it was so dominant. In our modern age where many of us cannot see any but the brightest stars, this is hard to imagine. But let us look at an image of the night sky.
You can see the Little Dipper with the end of its handle as the star, Polaris. You will see a ring and then a ring in dotted lines. The lavender ring is the horizon. The dotted ring is the plane of the ecliptic or the celestial equator. The plane of the Solar System on which the planets circle the sun like dots on a spinning disk is slightly tilted with respect to the plane of the galaxy. The band of stars around the middle of the celestial sphere or equator of the night sky is called the Zodiac. Most of you may know the Zodiac sign from astrology: Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius and Pisces. There are only two times a year when the Sun appears to us on Earth to cross the celestial equator. One time is the Vernal Equinox on March 20 or 21 and the other time is in fall on the Autumnal Equinox.
Here you can see the Earth as the center of a sphere. The disk is the "horizon" of our little space. Imagine standing in the center of this disk. You look out and see the sun around a flat disk. For now, let us ignore the fact that our world is tilted and just imagine the sun going around the sky against the tilted sphere of the stars. Imagine a disk rotating within a sphere. I have drawn the Little Dipper for you. You see that north is not overhead. The stars appear to spin around the Pole Star. The Little Dipper appears to revolve around all night around the handle or tail. You can also see that I have put in the equinoxes, the solstices and some holidays that our ancestors celebrated. Although my lines are not perfect, you can see that the equinoxes are when the path the sun (and planets) appears to take crosses the equator of the celestial sphere.
Here is a picture of our modern age of stars. The Vernal Equinox is in Pisces and the Autumnal Equinox is in Virgo. Precession happens to a spinning object when it is subjected to gravity. It begins to slow down and wobble. Imagine the disk of our star system being subjected to gravity and our world affected by the gravity of the sun and moon and planets. Everything is in motion and everything spins. One aspect of precession is that every 72 years the stars appear to slip backward one degree out of 360 degrees in the circle of the ecliptic. If we look at which star is hidden by the sun (or opposite the sun) on the Vernal Equinox, in 72 years it will have moved backward one degree. This does not seem like much, but over 720 years, it is ten degrees, and each sign of the Zodiac is only thirty degrees. Thirty degrees, twelve signs equals 360 degrees. So, in approximately 2160 years, the sun will hide an entirely different sign of the Zodiac at the Vernal Equinox.
Here is our Classical sky. This is the one you may know, because the Zodiac and astrology came from the alchemists who inherited it from the Persians and they from the Greeks. The Zodiac signs became fixed in the West so that Aries always rules those people born when the sun was in that sign from March 21 to April 21 even though today, the sun in is Aries from April 16 to May 16! The Age of Aquarius will take place in about 400 years when the Sun enters Aquarius on the Vernal Equinox. In India, they precess the equinoxes and use planet charts that are up to date for their astrology.
The other thing you should note in this drawing is the position of the Pole Star and the Little Dipper. This is the second aspect of precession which causes the wobble of the axis of the Earth in respect to the stars. It takes 26,000 years for the axis to make one rotation. Yet the ancients noted it. Because the celestial pole seems to shift, the horizon moves with it. Stars that were visible in ancient times now appear to be below our viewing horizon.
Although I have dated this image 2000 BCE,it is more like 2500-3000 BCE. This is the time of the great stone monuments in Europe and the building of the first pyramids in Egypt. This is also the time of Anieth. Although our Zodiac comes from the Greeks, most of our legends about the stars come from this time. This time was very important. Two stars that are directly opposite each other rule the Equinoxes: Antares in Scorpio and Aldebaran in Taurus. And you will note, the pole star is now the third star in the tail of the great serpent/dragon Draco. Draco appears to be chasing his tail. The skies changed so much in the last 5000 years that archeologists and astronomers did not begin to understand much of the purpose of the stone markers all over Europe until computers gave us the ability to precess a model of the night sky to this time. Suddenly, a host of legends became clear as well as some interesting facts about Stonehenge, Woodhenge, the White Horse and other Paleolithic sites.