The Constellations of the Zodiac.

By Michel Gravereau
Since the beginning of my articles, I have discussed the constellations, and often I talk about the Zodiac. Just last week, when discussing Jupiter and Venus, I placed them in Gemini.
Why do these constellations attract more attention than others?

Of course, everyone knows the Big Dipper, the Little Dipper, and the three constellations that house the three summer stars: Cygnus, Lyra, and Aquila.
Everyone also knows their Zodiac sign.

What is it, one of our brilliant leaders might have asked?
The Zodiac is the band of the sky where we see the Sun, the Moon, and the planets move, as seen from Earth. Indeed, since the solar system is relatively located on a disk, with the exception of Pluto, which is seen from Earth, they can only appear in the same "corridor." A highway, in a way, for our star, our natural satellite, and the other planets.

In antiquity, the Greek Hipparchus (2nd century BC) divided this band of the sky into twelve segments: the constellations of the Zodiac.

For reference, these are Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, and Pisces.

Since the Earth orbits the Sun in one year, from Earth, we have the impression that it is the Sun that is moving. Our brain sometimes gives us a strange impression. For example, when we are on a train or in a fast car, don't we have the feeling that "the scenery is passing by"? In reality, it is we who are moving.

Two thousand years ago, the Sun entered the constellation of Aries at the time of the Spring Equinox (around March 21st). Then, on April 21st, our star moved into Taurus. On May 21st, it was Gemini's turn to welcome the Sun. And so on.
This is partly why your Zodiac sign corresponds to the Sun's position in front of the stars of a constellation. But this is the Sun's position as it was two thousand years ago. Since then, nothing has changed in astrology.

However, astronomers have detected a movement of the Earth called the "precession of the equinoxes." This slow movement of the Earth's axis of rotation (one revolution every 25,735 years) causes a 30° tilt every 2,000 years, like a spinning top or a gyroscope.

This results in a different observation of the Sun's position for us, Earthlings of the 20th or 21st century, compared to what our ancestors could see. If I take my own case, born on May 7th, I am considered a Taurus by all astrologers. It is true that 2,000 years ago, the Sun was in front of the stars of the constellation Taurus.

But due to precession, today, May 7th, the Sun is in front of the stars of Aries. It will not enter the constellation of Taurus until May 14th. The same is true for all the other constellations, although there is a 58-day overlap for the year.

Let's also not forget that the Sun doesn't just visit twelve constellations, but thirteen. Indeed, between December 1st and 18th, the Sun passes through the constellation of Ophiuchus, known as the Serpent Bearer in English. This ancient constellation was already identified by Claudius Ptolemy 22 centuries ago. It represents the Roman god of medicine, Aesculapius (Aesculapius) for the Greeks, who holds the head and tail of the Serpent. The Serpent, or Caduceus, is a symbol for physicians.

So that everyone can know the Sun's position on their birthday, here are the exact dates of the Sun's entry into the constellations of the Zodiac:

Capricorn January 19th;

Aquarius February 16th;

Pisces March 13th;

Aries April 19th;

Taurus May 14th;

Gemini June 21st;

Cancer July 21st;

Leo August 10th;

Virgo September 16th;

Libra October 31st;

Scorpio November 23rd;

Ophiuchus, November 30;

Sagittarius, December 18.