For several years I’ve known there has been something (I wasn’t sure what) about a possible thirteenth sign of the zodiac. Last week I googled “13th zodiac” and came across several sites mentioning Ophiuchus, the serpent-bearer. If I am reading the conflicting information correctly, Ophiuchus is an actual constellation near Scorpio and Libra and is now considered by some to be a sign within the astrological zodiac. 

Finding information about Ophiuchus took me about a minute, which should have been the end of it. Unfortunately, one of the websites stated that the change in the zodiac was initiated by NASA, and I could not leave this odd assertion unexplored. 

I searched for a website that was not entirely astrological and found a short 2020 Time Magazine newsfeed reporting that NASA disavowed any involvement in changes to the astrological charts. According to the short article, a NASA representative was quoted as saying, “We see your comments about a zodiac story that re-emerges every few years. No, we did not change the zodiac.”* When I read this, I could not help but imagine a group of NASA astronomers drawing straws to determine which one of them was going to ruin his or her career by going before cameras to explain the space agency’s views on astrology. 

Time Magazine, however, was not the end of my internet surfing. Two of the articles about Ophiuchus had used the word “sidereal.” I’d never seen this word before, so I looked it up. It means “with respect to the distant stars” and refers to all of the sky other than the sun and the moon. When I saw that the sidereal day is slightly shorter than the normal day (23 hours 56 minutes 4.091 seconds), my first thought was that this must be the reason for leap year. 

Leap year, of course, has nothing to do with the length of the sidereal day, but with the time it takes the earth to travel around the sun. Had I taken even a moment to think about it, I would have realized it on my own. Still I googled “leap year” and, in doing so, learned something that genuinely surprised me, largely because it seems like something I should have already known. 

The solar year is 365.25 days long, not 365.0, so every four years we add February 29 to the calendar. This is common knowledge. Less known, however, is that fact that the solar year is not exactly 365.25 days, but 365.25 days minus 11 minutes. This means that adding a day to the calendar every four years actually overcompensates by more than a half hour every four years. To adjust for this minor miscalculation, three leap years every 400 hundred years get skipped, and it always occurs during the last year of a century. There was no leap year in 1700, 1800, and 1900. The year 2000, the one change of century in my lifetime, was the exception. It did include an extra day in February.** With all of the hype about the new millennium and Y2K, no one had mentioned that having 366 days in a year ending with two zeros was an anomaly. 

After wasting forty-five minutes traveling down various astrological/astronomical rabbit holes, the most disturbing part of the whole thing was learning that the insertion of Ophiuchus into the zodiac bumped all of the other signs over a peg – and, as a result, I was no longer a Gemini. I don’t believe in astrology and I do not identify with most of the characteristics generally associated with Gemini, but neither was I willing to change my sign at this point in my life. I’m too old to have to learn what it means to be a Taurus. Therefore, I am concluding that the people advocating for Ophiuchus must be wrong.

I am married to a Taiwanese woman, and the Chinese zodiac is more a part of my life than the Babylonian zodiac. Sunday was Chinese New Year, and it is now the Year of the Rabbit.  Xīn nián kuài lè (新年快樂). Happy New Year. 

* Locker, M. July 17, 2020. “NASA Elegantly Shuts Down Those New Zodiac Star Theories. Time Newsfeed.  Found at:

**Found at: 

Steven Simpson