I’m an Ophiuchan

Seth Jarvis

A billion years ago, on January 26th, I was in the early days of my career at the old Hansen Planetarium and I got a phone call from a woman with a question.

“My sign is Aquarius, but today’s my birthday and I just learned that the Sun is in Capricorn today.  Why is the Sun in the wrong place for my sign?”

I was happy to explain.

“The signs of the zodiac and the calendar dates associated with them were created more than three thousand years ago.  Since then the axis of Earth’s rotation has shifted quite a lot.  Think of the way a spinning top slowly wobbles so that the top’s axis of rotation is moving in circle.

“Earth experiences this slow movement of its spin axis, too.  This drifting of where the axis of rotation is pointing is called the Precession of the Equinoxes.  

“A complete precession cycle takes about 26,000 years.

Earth's axis of rotation takes about 26,000 years for a complete presession cycle.

Earth's axis of rotation takes about 26,000 years for a complete presession cycle.

“From one January 26th to the next there’s not much of a change in where the Sun is along the zodiac, but in the last three thousand years the position of the Sun in the sky on any particular date has changed by more than one whole sign of the zodiac.”

My caller wasn’t happy about  this. “This just makes a mess out of everything,” she said. “I’m going to have to check with my astrocartographer.”

“Astrocartographer?”  I asked, bracing myself for the response.

“You know, deciding where you should live, based on your horoscope,” she explained.

Being young and tactless, I blurted out something like, “Are you serious?”

“Oh yes!” she said. “It works!  I used to live in Aspen, but I was having a terrible time there.  My astrocartographer said that I’d be happier in Park City, so I moved here and life is great!”

My underdeveloped capacity for impulse control got the better of me.  “Does an astrocartographer ever recommend that someone move from Aspen to Des Moines?”

“I don’t think that’s funny at all,” she said – and hung up.

That was my first encounter as an astronomy educator with someone who took astrology seriously.

During my second encounter, an honest-to-gosh debate in front of an audience at a local library, I laid out all kinds of rock-solid evidence that astrology is so much mumbo-jumbo with no basis in reality.

The audience said I won the debate on the preponderance of evidence presented, but afterwards, as the astrologer and I walked out of the building to our cars, I noticed that the astrologer got into a spanking-new silver Mercedes.

I drove home in my rusting VW Beetle, thinking hard about who really “won” the debate that night.

And now the zodiac is back in the news.

It seems that someone is yet again pointing out what astronomers have known for centuries, that the precession of Earth’s poles makes determining horoscopes a bit of a mess, and that if we’re going to be honest with ourselves we need to slip a 13th zodiacal sign, Ophiuchus (“Oh-fee-yoo-kus”), in between Scorpius and Sagittarius.


I’ve known all along that on my birthday the Sun isn’t really in Sagittarius, as the newspaper horoscopes claim it is, but in Ophiuchus.

That’s right, I’m an Ophiuchan.

Now that the subject has made the news, and in the interest of promoting greater public awareness of the cosmos, I offer here the astronomically accurate zodiacal calendar.  These are the constellations where the Sun actually is on the following dates:

Pisces:                  March 13 – April 18

Aries:                    April 19 – May 14

Taurus:                 May 15 – June 21

Gemini:                 June 22 – July 20

Cancer:                 July 21 – August 10

Leo:                       August 11 – September 16

Virgo:                    September 17 – October 31

Libra:                     November 1 – November 23

Scorpius:              November 24 – November 30

Ophiuchus:         December 1 – December 18

Sagittarius:          December 19 – January 19

Capricorn:           January 20 – February 16

Aquarius:             February 17 – March 12

If you believe in astrology, then I’m unlikely to be able to use reason and scientific evidence to dislodge an idea that reason and scientific evidence played no part in creating.  If you think the position of hunks of rock and clouds of hydrogen millions or billions of miles away should guide your real estate decisions, that’s your call.

If you don’t believe in astrology, then you probably already know that astrology fails every scientific test it’s ever been given, and I don’t need to rehash them here.

But if, for some reason, you want to know the many, many ways that astrology has been proven to have no connection to reality, you can start here, and I’ll leave it at that.

At least you now can know what your “true” birth sign is.

Tags: , , , , ,

4 thoughts on “I’m an Ophiuchan

  1. What! I’m a Libra? Oh man, I always thought it was cool being a Scorpius, scorpions and all. Now I’m some ‘scales of justice’ thingy? Not even a bright star in that constellation. How degrading…

  2. Science used to think Pluto was a Planet too, that’s what we were taught as kids anyway. Nothing is a sure thing in this world. We should just get used to it. I hate my “new” sign too.

  3. Rosey,

    You raise an interesting observation – scientific classification can change with the discovery of new information. That’s the cool thing about science; it self-corrects and abandons old ideas when presented with better information.

    Yep, when Pluto was discovered in 1930 it was called a planet because at that time the only things known at that distance from Sun were planets or comets, and Pluto didn’t look or act like a comet.

    In the 1930′s astronomers had no idea about the Kuiper Belt or Trans-Neptunian ice balls.

    BUT, even in the 1930′s some astronomers had their doubts about Pluto’s status as a “planet.” This is from the November, 1934 issue of “Science and Mechanics” magazine:

    “Since his discovery, the planet Pluto has been a good deal of disappoint to his sponsors. Now Dr. Baade, of Mt. Wilson observatory, estimates that Pluto’s mass is something like that of Titan, the largest satellite of Saturn… So that Pluto ranks as the largest asteroid, rather than the smallest planet; and it may be necessary to look farther for unknown planets.”

    Most astronomers were not surprised when the observational evidence for countless other Pluto-like ice balls beyond Neptune’s orbit became so overwhelming that a demotion of everyone’s favorite planet to “Dwarf Planet” status became necessary. The astronomers were just being honest about the data.

    Science isn’t a fixed body of knowledge, it’s a dynamic, self-correcting process for uncovering the truth.

    The same can’t be said for astrology.

    Did astrologers announce that horoscopes created prior to the discovery of Uranus in 1781 and Neptune in 1846 were wrong? Nope, they just added two new worlds to their pseudo-science and kept churning out the same nonsense.

    If you don’t like your astronomically correct birth sign, I wouldn’t worry about it. One’s just as good as another.

    Then again, why not find where the Sun was in the sky on your birthday, see what stars are nearby, give yourself a new “Star Sign” and invent your own personal horoscope?

    (Putting on my “think-like-an-astrologer-hat”)

    On my birthday the Sun was close to the star Sabik, which to the ancient Chinese was the “Left Wall of Heavenly Market Enclosure.”

    I’m left-handed, and my 401k tanked in the stock market mess of 2009, thus confirming my “astronomically correct Star Sign horoscope.”

    See? Astrology works!

    (Takes off think-like-an-astrologer hat)

    Hey, wait a minute!

Leave a Reply

Your email address will not be published. Required fields are marked *


You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>