center of the galaxy - milky way nightsky on a clear night wider shot many stars

The tradition of reading the stars: The myths behind astrology

Have you ever been asked, “What’s your sign?” It’s likely you know at least one person who’s engrossed in astrology—the forecasting of earthly and human events through the observation and interpretation of the fixed stars, the sun, the moon and the planets—but you may not have a grasp on whether any of it is real.

Headshot of Stacy McGaugh
Stacy McGaugh

The short answer is, no, there is no scientific basis for astrology. One thing remains true, though: Humans have obsessed about the sky forever. To get a glimpse into the myths behind astrology as many recognize World Astrology Day today (March 21), The Daily spoke with Stacy McGaugh, professor and chair of astronomy in Case Western Reserve University’s Department of Astronomy

“I will give the astrologers credit for keeping track of where things are in the sky,” McGaugh said. “They care about the observational details, and they get them right. Where Mars and Jupiter and Venus, etc. are relative to the constellations of the Zodiac is fundamental observational astronomy. That said, the interpretive veneer using this for fortune telling is complete and utter bunk.”

Read on to gain McGaugh’s take on two aspects that help explain humans’ fixation on celestial bodies. 

1. The planets and phases of the moon used to be clearly visible before light pollution. 

We have polluted our skies with so many lights that many people have never even seen the Milky Way. These things were right in our face every night for all of history before lights became ubiquitous in the past 150 years or so. Everybody could see the planets and the phases of the moon and the seasonal north-south progression of the location of sunrise and sunset, so it is easy to understand why it is tempting to ascribe meaning to our lives that isn’t there. 

After all, there is meaning that is relevant to the lives of early agrarian people, the progression of the seasons being important indicators of when to plant and when to harvest. So, maybe it isn’t unreasonable to imagine that relatively rare but predictable events Mars and Saturn being in conjunction also have significance to our lives, but they don’t. The stars are not the boss of you.

2. Some of the first written documents are elaborate tables of eclipse cycles. 

Some of the first written documents (tablets from ancient Babylon) are elaborate tables of eclipse cycles. Holy moly—there’s a chance the sun will go dark at these times! That was important enough to be one of the first things written down when writing was first invented. (Accounting too; lots of early tablets are essentially Excel files of who paid who for what, and who still owes us.) 

The sophistication of the early eclipse tables implies to me that people had been keeping accurate oral records for a long time before writing was even invented, because one needs centuries of observations to work out all the relevant cycles—cycles they already knew quite accurately. E.g., the Saros cycle is 18 years while the Metonic cycle is closer to 19; you need to have kept careful track of the sky for many cycles to recognize them and measure their length. 

The observational aspects of astrology are very much in this great, long tradition. The urge to read human events as writ large on the sky is more a projection of the human ego.