If I were to ask anyone their Zodiac sign, most people would be able to answer right away. What if I told you that what you thought was your astrological sign may not be true? According to the science of astronomy, whether a Taurus, Pisces, or Libra, your Zodiac sign is not what you believe it to be. To be considered a Scorpio, for example, the sun must have been located in the constellation of Scorpius when the person was born. Throughout the year, the location of the sun changes as the sun follows a path in the sky known as the “ecliptic”. This path crosses through all of the 12 Zodiac signs, spending about a month in each sign before crossing over to the next. This is how we why we determine our sign based off what day we were born. Unfortunately, the location of the sun no longer corresponds with the dates originally associated with each sign.
To understand why these dates are off, we need to look into a physical process known as “precession”. The Earth rotates on an axis that is at an angle of 23.5º which means that the Earth is titled off center. As the Earth rotates, it also wobbles on this axis similar to how a top would wobble if it were off-center. This causes our axis to point at different places in space as thousands of years pass. An example of this precession can be seen if we look at Polaris, commonly called the North Star. As years pass the location of our north celestial pole changes, meaning that Polaris was not always our north star, and over the course of a couple thousand years it will again cease to be the celestial north pole. In approximately 13,000 years the north star will be Vega, a star within the constellation of Lyra. A complete precession takes approximately 25,000 years which means that in another 25,000 years, Polaris will be the north star again. But how does this relate to astrology?
The dates used in today’s astrology were assigned over 2,000 years ago. Due to the precession of the Earth, the sun’s location now appears in the sky approximately one month earlier than where it was 2,000 years ago. There is also an additional sign that you may have heard about called Ophiuchus, the serpent wrestler. Ancient astrologers did not account for Ophiuchus because they, like us today, believed 13 to be an unlucky number. Furthermore, since 13 would not divide the signs then easily between elements (air, fire, earth, and water), it was left out of the Zodiac.The ecliptic however, does actually travel through this 13th sign, and should be counted among the other Zodiacal signs as the sun spends a significant amount of time in it. Knowing these changes, the accurate signs are actually:
Capricorn: January 19 to February 16
Aquarius: February 16 to March 11
Pisces: March 11 to April 18
Aries: April 19 to May 13
Taurus: May 14 to June 19
Gemini: June 20 to July 20
Cancer: July 21 to August 9
Leo: August 10 to September 15
Virgo: September 16 to October 30
Libra: October 31 to November 22
Scorpio: November 23 to November 29
Ophiuchus: November 30 to December 17
Sagittarius: December 18 to January 18
As you can see, the Zodiac is not exactly what it seems. Presented with these facts, I will let you decide your own beliefs. Looking at the facts, my belief is that astrology holds no bearing on how you should live your life. But I, for one, will continue to read my horoscope- it’s just a lot of fun.
This article was written by Mikayla Cleaver ’19.