They were chosen because these are the signs that the ecliptic of the sun moves through them… And because the Earth’s Pole points towards these signs as it wobbles around…
So there are 12 signs of the zodiac.
They were chosen because these are the signs that the ecliptic of the sun moves through them [Yellow].
And because the Earth’s Pole points towards these signs as it wobbles around [Blue].
Giving these constellations an energy storehouse of direct sun energy.
Therefore causing more of an effect on earth as they are stronger. Though the sun actually goes through 13 signs. NOW. The reason why the 13th sign Ophiuchus isn’t added is because he is fused into the definition of Scorpio already.
So if you have 13 signs, you lose being able to have basic compatibility and qualities. Ancient mathematicians realised that 12 is a number earlier to break apart into things like elements (4×3) and qualities (3×4). 13 cannot be broken up like that.
And so when astrology was originally founded, to approximate, there was the thirty degrees of the sky that Ophiuchus (Ophi) and Scorpio shared. So at that time Ophi was about 5 degrees, and Scorpio about 25 degrees. So they infused the two together but used the constellation of Scorpio as the title as it was dominant.
So now, it is the opposite, Scorpio is about 5 degrees and Ophi about 25.
This means Scorpio can also be called Ophiuchus, do as you like.
But so the meaning doesn’t change though, cause Ophiuchus was always included and known.
So Scorpio is known as the Healer. Ophiuchus is known as the Healer.
The only difference is that Ophi is given a less pessimistic show. If that makes sense, people see him as the redeemer.
But if you know about Scorpio, you know this already. That Scorpio has three parts, the dove/phoenix, the eagle and the scorpion. It is known for its ability to dig deep into the darkness to heal and transform things. The alchemist who can transmute.
The pessimist who can fix all your problems (a mighty fine compliment).
Scorpio’s think in black and white, so think of the darkness and Mars qualities as the Scorpio side and Ophiuchus as the white, after healed, side. As an idea. Though both are innate to Scorpio itself.
Its just that Ophiuchus and Scorpio share the same part of the sky.
Brothers if you will.
All signs have something in common, whether its element, quality, planet or just that a person is born human as well, ie, you both can speak.
But from the get-go Scorpio and Ophiuchus were fused, so all that you know, is what they are together.
(c) Watcher, S, 2014. Why are the Constellations chosen? www.freesiderealastrology.com ONLINE]. https://www.freesiderealastrology.com/why-are-the-constellations-chosen/