The term and concept of zodiac and zodiac constellations appeared for the first time in Babylon about three millennia ago. Babylonians used a twelve-month calendar, thereafter 12 moon phases, so it was very convenient to divide the zodiac equally into twelve parts in such a way that each sign correspondents with one month. The word “Zodiac” is Greek and means “cycle or circle of little animals».
Actually, ancient astronomers numbered 13 zodiac signs, but they had to opt out of one for the sake of convenience.
Even after this some signs were still beyond their segments. For example, the Sun points to Virgo for 45 days, but it points to Scorpius for only 7 days, and to Ophiuchus — for 18 days. To make the periods more equal, it was simplified and Ophiuchus was eliminated. The zodiac we used to know has 12 signs: ♈ Aries, ♉ Taurus, ♊ Gemini, ♋ Cancer, ♌ Leo, ♍ Virgo, ♎ Libra, ♏ Scorpio, ♐ Sagittarius, ♑ Capricorn, ♒ Aquarius, ♓ Pisces.
The picture has changed a bit thus far. The matter is the axial precession: there’s a slight displacement of the Earth's axis can be observed during its rotation, which causes a slow zodiac signs shifting. In ancient times people couldn’t even imagine such phenomena. That’s why the actual picture of zodiac differs a bit from a traditional one. It should therefore not be surprising this page and Unicode contain 13 signs. Welcome back, ⛎ Ophiuchus!
Any sign can be copied and pasted to ornament your nickname or Facebook profile. Don’t forget to check your zodiac sign out first. Who knows, might be you’re not Scorpio any more 😉