Astrology and Astronomy have a few essential differences. Astrology is an ancient practice that predicts people’s fate and fortune by studying the positions of the stars, planets, Moon, and Sun.

Back in the day, astrology was combined with astronomy to make scientific observations that are still valuable now. 

However, Copernicus, Kepler, and Galileo realized the planets orbit the Sun and not the Earth as people assumed. 

Also, Newton discovered the physical laws that govern their movements, leading to the separation of astronomy and astrology forever.

Nowadays, astronomy doesn’t agree with the zodiac dates, one of the basic principles of Astrology. In this article, we are going to explain why.

The constellations of the zodiac

The Sun passes through 12 constellations in the sky for a year that is known as the zodiac. It consists of animal figures like the lion (Leo), the Crab (Cancer), or the fish (Pisces).

According to a Greek phrase, even the word “zodiac” means “circle of animals.” Although these constellations seem definitive, there are many others produced by different cultures in the world, which have their own concept of how the sky is formed.

Just to take one example, the Incas made constellations from dark patches in the Milky Way instead of the stars.

The number of constellations that constitute the Western Zodiac is based on the cycles of the Moon, which orbits the entire Earth more than 12 times a year.

Basically, the Sun passes through a different constellation every new Moon. Although nobody can see the stars during the daytime, you can realize what constellation the Sun is by looking at the sky at night.

For example, if the Sun is in Pisces, at night, you’d see the opposite sign, Virgo. Each zodiac sign fits into a 30-degree portion of the sky, which if you multiplied by 12, you get a total of 360 degrees.

However, this is not entirely true, as every constellation varies in its shape and size. For example, the Sun goes through the Scorpio constellation in five days but takes up to 38 days to pass its opposite sign, Taurus.

This is just one of the reasons zodiac signs do not line up with the constellations.

Precession of the equinoxes

A wobble in the Earth’s rotational axis makes astrological signs don’t line up with the zodiac. It’s called precession. The Earth bulges at the equator as a result of its rotation, and the gravity of the Sun and the Moon pulls on the bulge, causing the planet Earth to wobble.

This causes the Earth’s axis to swing in a circle over 25800 years.

A wobbling Earth is responsible for the zodiac dates to differ from those established back in the day. This movement makes the constellations look to slide to the east a degree per human lifetime.

A long time ago, the first day of spring was in Aries, but because of precession, it moved into the sign of Pisces around 100 B.C., and it will remain there until 2700 A.D. 

In 25800 years, it will return to Aries, and the whole cycle will begin again.

What constellation was the Sun in on your birthday?

These are the correct dates for people living today, but these dates will continue to change.