The zodiac is a strip of the sky limited by two parallels of celestial latitude, one located 8º to the north and the other 8º to the south of the ecliptic, where the Sun, the Moon and the planets always travel. In its apparent annual movement across the sky, the Sun draws a trajectory, which is called ecliptic, which crosses 13 zodiacal constellations: Pisces, Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpius, Ophiuchus, Sagittarius, Capricornus and Aquarius.
A sign corresponds to the constellation in which the Sun was on the day you were born. It was the Babylonian astrologers and, later, the Greeks who defined the 12 traditional zodiac signs, more than 2000 years ago. However, this is at odds with astronomy.
First, astrology suggests that each sign of the zodiac fits perfectly in a 30º slice of the sky that multiplied by 12 adds 360 degrees. In reality, this is not the case, as the constellations vary greatly in shape and size, so that the Sun does not take the same time to travel through each one. Perhaps, this desire to divide the celestial sphere into equal parts was one of the motivations that led the ancient Babylonian astrologers to skip one of the 13 constellations: Ophiuchus (serpentarium).
Second, the main reason astrological signs do not align with the zodiac, however, is an oscillation on the Earth's rotational axis called precession, which is caused by the Moon's gravitational pull on Earth's equatorial protuberance. This oscillation causes the Earth's axis, which is the central line around which it rotates, to oscillate in a slow cycle over 25,800 years. This movement alters the view of the Earth's zodiac. The first day of spring in the Northern Hemisphere was marked to be the zero point of the zodiac, astronomers call this the vernal equinox and it occurs when the ecliptic and the celestial equator intersect on approximately March 21. Around 600 BC the zero point was in Aries and was called "the first Aries point". So, due to precession, the zero point of the zodiac, which was previously in Aries, moved to Pisces around 100 BC, where it is now and will remain until 2700 AD, when it will change to Aquarius and so on until, after 25,800 years old, he returns to Aries and the cycle begins again.
A sign corresponds to the constellation in which the Sun was on the day you were born. It was the Babylonian astrologers and, later, the Greeks who defined the 12 traditional zodiac signs, more than 2000 years ago. However, this is at odds with astronomy.
First, astrology suggests that each sign of the zodiac fits perfectly in a 30º slice of the sky that multiplied by 12 adds 360 degrees. In reality, this is not the case, as the constellations vary greatly in shape and size, so that the Sun does not take the same time to travel through each one. Perhaps, this desire to divide the celestial sphere into equal parts was one of the motivations that led the ancient Babylonian astrologers to skip one of the 13 constellations: Ophiuchus (serpentarium).
Second, the main reason astrological signs do not align with the zodiac, however, is an oscillation on the Earth's rotational axis called precession, which is caused by the Moon's gravitational pull on Earth's equatorial protuberance. This oscillation causes the Earth's axis, which is the central line around which it rotates, to oscillate in a slow cycle over 25,800 years. This movement alters the view of the Earth's zodiac. The first day of spring in the Northern Hemisphere was marked to be the zero point of the zodiac, astronomers call this the vernal equinox and it occurs when the ecliptic and the celestial equator intersect on approximately March 21. Around 600 BC the zero point was in Aries and was called "the first Aries point". So, due to precession, the zero point of the zodiac, which was previously in Aries, moved to Pisces around 100 BC, where it is now and will remain until 2700 AD, when it will change to Aquarius and so on until, after 25,800 years old, he returns to Aries and the cycle begins again.
Show More
