Chabot College - Scott Hildreth

Where was the Sun when you were born?

The question of all questions for humanity, the problem which lies behind all others and is more interesting than any of them, is that of the determination of man's place in nature and his relation to the cosmos.- T.H. Huxley

Many people confuse astronomy and astrology; after all, they both begin with the root "astr", which comes from Greek meaning "star".   Astronomy is defined generally as the scientific study of the universe, including the solar system, stars and galaxies.  Astrology is defined as any of several traditions or systems in which knowledge of the apparent positions of celestial bodies is held to be useful in understanding, interpreting, and organizing knowledge about reality and human existence on earth.  While both involve the study of positions of planets and stars, they are still very different ideas.  In this assignment you'll explore a bit about "sunsign" astrology.

Assignment Summary:  Two Things to Do!

For Part A (10 points), we will do this activity in our on-campus class, but online students will need to do it on your own - you can email me if you have problems, or post in Canvas for help. 
Everyone needs to do it, and record both your answers to the six questions here, and the answers from at least one other friend or family member.  Please record who you talked to, their answers to the same 6 questions, and most of all, capture their reactions when you showed them the Sun's actual position on their Birthday. 

If they ask you WHY the zodiac constellations are no longer aligned as they were 2000 years ago, you might want to read a bit about precession in our book, or online!  We'll talk more about that in class next week, and you'll read about in the first chapters of our text.

For Part B (10 points), read one of the two short pieces about astrology linked below, and provide your reactions, as well as the citation for the reference(s) you read.   Remember you can use the citation guide provided at my website if you aren't sure how to cite online resources.

"Astrology: Is it scientific?" Understanding Science. University of California Museum of Paleontology. 28 January 2014.


Fraknoi, A. (ed.) (1988) Horoscopes vs. Telescopes, a Focus on Astrology.  The Universe in the Classroom. No. 11  Astronomical Society of the Pacific.

Share in a short paragraph your opinions of the article, and whether it makes a convincing case to you that Astrology is or is not "scientifically" valid.   Be sure you include some specific comment in your essay about what you read. Finish your essay by answering directly whether something being valid scientifically is important to you? 

On-line classes: Please POST your assignment on Canvas in the discussion forum directly, not as an attachment.

On-campus classes
  Please remember to TYPE your answers, and print a copy double-spaced and spell-checked; aim for at least 250 words (about 1 page is fine), with citations for any outside references used other than the textbook. If you are absent from class  by the due date, please post your assignment in Canvas in the discussion board, but please then bring your work on paper to the next class so that I can grade it!  I won't grade the work submitted on Canvas for on-campus classes - it just establishes that you completed and submitted it on time.  Please recognize that coming to class and participating in the discussion we will have is *part* of the assignment, so missing class on the day it is due will possibly affect your score.

Part A. (Investigation) Where was the Sun (really!) when you were born?

Question 1:  Do you believe in astrology? Do you read your horoscope?  Do you *believe* it? :)  Why or why not? 

(answer in a few sentences - this doesn't need more than a paragraph.)

Now that you have shared your feelings about Astrology, try this activity with your Star and Planet Locator. (If you did not purchase an Edmunds Star and Planet Locator,  mentioned in the syllabus, and available in the bookstore as well as online, you can use online tools to accomplish this activity. Check out the WebLinks in the Canvas site for help! You can use the free Skymap app ( at ), or the Neave planetarium app (but it doesn't label the constellations). I've pasted images from these tools below for your reference.  Or look at my guide about using the free Astroviewer java application which will run in Microsoft's Explorer Browser just fine, but not Chrome) .

Most people can name their "Sun Sign" - the constellation of the zodiac supposedly nearest the Sun on their date of birth. Astrology columns in the newspaper and magazines use this sign to establish general personality characteristics, based on the twelve zodiacal constellations:

 Aries (Ram) Mar. 21 - Apr. 19
 Libra (Scales) Sep. 23 - Oct. 22
 Taurus (Bull) Apr. 20 - May 20
 Scorpio (Scorpion) Oct. 23 - Nov. 21
 Gemini (Twins) May 21 - Jun. 20
 Sagittarius (Archer) Nov. 22 - Dec. 21
 Cancer (Crab) Jun. 21 - Jul. 22
 Capricorn (Goat) Dec. 22 - Jan. 19
 Leo (Lion) Jul. 23 - Aug. 22
 Aquarius (Water Bearer) Jan. 20 - Feb. 18
 Virgo (Maiden) Aug. 23 - Sep. 22
 Pisces (Fish) Feb. 19 - Mar. 20

Question 2:  What is your birthdate  (month & day only - you don't need the year!) and your astrological sun sign based on the table above?

(answer by providing your month and day of your birth, like "August 29th" or "8/29".)

But is this really the constellation "behind" the Sun when you were born?  Let's find out.

First, set your Edmunds Star and Planet Locator by rotating the blue calendar wheel so that your birthdate is next to NOON (close to the corner marked South). At Noon, we know (regardless of the date) that the Sun is on the meridian, the line running from North to South, dividing our sky into two hemispheres. The AM side (for "ante-meridian") is the side of the sky closer to the Eastern horizon; when the Sun is on this side of the sky, it is before Noon. The PM side (for "post-meridian") is the side closer to the West - the afternoon side.

What if you weren't born right at noon on your birthday?  Will it make a difference in the constellation the Sun appears in front of?  We'll see a bit later!


 Next, imagine a line running through the sky on your Locator from the north to the south.   This is your meridian.  The Edmund's  Locator has string holes that could be used to create this meridian line! At noon, the Sun will be somewhere on this line.



Now Look for the ecliptic line on your Locator - it will be a dashed line labeled ECLIPTIC and you will see it running across the Locator at a slight angle from east to west. The ecliptic is the line representing the Sun's path across the sky during the year. So the Sun can always be found on the ecliptic.  




Mark the point on your Locator's sky where the ecliptic and the meridian cross. On your birthday, that is where the  Sun was! Now look at the zodiac constellation at or near that point  - one of the 12 constellations in the table at the start of this activity.  Find the closest one.  If you are EXACTLY between two, note that.  This will be your actual Sun sign!


Question 3: What is your actual Sun sign, based on the star locator?  Is it the same as the one you thought was "yours"?

Answer with the zodiac sign you see at the intersection where the ecliptic and meridian cross.  And answer "Yes/No" if it is the same as the sign you THOUGHT was yours.  And MOST importantly, please capture in a sentence or two the reaction of those you did this test with!  Were they surprised?  Did they doubt you (or the Star Locator or App)?  Did they refuse to believe and GOOGLE the question themselves?  Are they now refusing to talk with you? :)


For most people, the predicted sunsign based on your birthdate will NOT line up with where the Sun actually was on your birthday.  Some folks born in front of large zodiacal signs, like Pisces and Virgo, may still see the sun in front of "their" astrological sunsign, but this is more an accidental result of the constellation being rather large. Folks born under the smaller signs of Aries or Cancer, for example, will typically NEVER find that the Sun actually was in front of those sign.

TODAY (c. 2000 C.E.)
Constellation Date Span Days Constellation Date Span Days
Aries 21 Mar - 19 Apr 30 Aries 19 Apr - 13 May 25
Taurus 20 Apr - 20 May 31 Taurus 14 May - 19 Jun 37
Gemini 21 May - 20 Jun 31 Gemini 20 Jun - 20 Jul 31
Cancer 21 Jun - 22 Jul 32 Cancer 21 Jul - 9 Aug 20
Leo 23 Jul - 22 Aug 31 Leo 10 Aug - 15 Sep 37
Virgo 23 Aug - 22 Sep 31 Virgo 16 Sep - 30 Oct 45
Libra 23 Sep - 22 Oct 30 Libra 31 Oct - 22 Nov 23
Scorpio 23 Oct - 21 Nov 30 Scorpius 23 Nov - 29 Nov 7
      Ophiuchus 30 Nov - 17 Dec 18
Sagittarius 22 Nov - 21 Dec 30 Sagittarius 18 Dec - 18 Jan 32
Capricorn 22 Dec - 19 Jan 29 Capricornus 19 Jan - 15 Feb 28
Aquarius 20 Jan - 18 Feb 30 Aquarius 16 Feb - 3/11 24-25
Pisces 19 Feb - 20 Mar 30-31 Pisces 12 Mar - 18 Apr 38

For more information about astrology, you might want to read:

    And you might enjoy seeing how the actual sun's position has shifted over the years because of precession, and the accompanying table of "dates" according to its author, Daniel Delaney. 


OK...So Why is my sign different???

In most cases, you will find your expected sunsign from the newspaper or usual astrology portal will NOT match where the sun actually was when you were born.  In a few cases, it is possible for the sign to be the same - especially if the zodiac constellation was large (like Leo or Pisces).  So how can we account for the difference scientifically?  Could it be:

a) The test is flawed!  I wasn't born at Noon, so this won't work!
b) The test is
flawed!  I was born somewhere else in the world, not at Chabot College!!


c) The test is valid - there must be some other explanation!

Let's take each of these options in turn!  In your response, please include your own personal answers, as well as those of your survey participants.

Question 4: (OPTION A)  Do you think the results in the above activity depend on what time you were born? Why?

In other words, if you were born at night, would the position of the Sun be in front of a different background constellation than if you were born during the daytime?  Record either Yes or NO,
and one sentence about why you think that would be so.

 Yes - I do believe that what TIME of day I was born affects my sunsign.

 No - I don't believe what TIME of day I was born affects my sunsign.

Most people DO believe their results depended on what time they were born, but that is NOT true!  Yes, the Sun does change its position in the sky; we see the Sun rise and move and set in the sky every day.  But we cannot see the stars behind the sun in the daytime, and if we did, we would see that they, too, are rising and moving and setting, just like the Sun, all because of Earth's daily rotation.

OPTION A Critical Test

 One way to see that the time when you are born doesn't affect your sunsign is to set the locator one entire day later, still at noon.  Again find the intersection of the ecliptic and meridian lines, which represents where the Sun has moved in 24 hours.  Try that now, and record your answers and those of your participants:

 ==> What is the sun sign you would have if your birthday was one day - 24 hours - later?  

==>  Does the Sun move very far in front of the background stars in 24 hours? 

==>  So would the Sun be in front of an entirely different zodiac constellation in just a few hours?

You should find that the Sun does NOT move in front of a different zodiac constellation in just one day - it takes many days to slowly pass in front of the background stars of a constellation (as Earth orbits!).  As seen from earth, the Sun does move around the ecliptic, but it takes an entire year.  Note that based on the zodiac sunsign table above, the sun appears to spend about 30 days or so "in front" of each of the twelve zodiac signs - even though the actual constellations are different sizes, and the Sun will spend many more days in front of Virgo and Pisces than it will Aries or Libra.

Question 5: (OPTION B)  Do you think the results in the above activity depend on where you were born? Why?

 Yes - I do believe that where I was born affects my sunsign.

 No - I don't believe where I was born affects my sunsign.

Many people DO believe their results depended on where on Earth they were born, but that is NOT true!  To see this, you need to make a scale model of the Earth relative to the Sun, and the textbook shared in the initial chapter one scale you could try.  If the Sun was the size of an orange (or the orange nerf ball I used for our on-campus demonstration!), the Earth would be the size of..... a grain of Cream of Wheat!  (Or, salt, if you don't have COW!) 

OPTION B Critical Test

Make a model using an orange (or softball, or any round ball about 3-4" across) to represent the Sun, and a grain of salt or Cream of Wheat to represent the Earth.  Hold the grain at least 10 large paces away from the ball (this should be across a normal room).  Ask your participants to visualize standing on that grain, looking at the Sun, and behind it, at even more distant objects (like a wall, or out a window).  Those more distant things would represent the stars of the background zodiac constellations (and in reality, those stars are farther away than El Paso, Texas on this scale! :) 

Record their answers to:

 ==> Do you think standing on different parts of the tiny grain of salt/COW would change the direction of where you see the Sun in front of the background wall/window/distant objects?  

==>  So would the Sun be in front of an entirely different zodiac constellation on the day you were born if you were born elsewhere on Earth?

You should find that the Sun does NOT appear to be in front of any different constellations no matter where you stood on the tiny grain of Cream of Wheat (or whatever you used to represent Earth!).  This is the value of making a scale model in science - they help us "see" things more accurately as they are. 

Question 6: (OPTION C)   If the test you have done IS valid, and there must be some other explanation as to why the actual sunsign does NOT match the astrological sign we typically use.  To explain why your actual sign is most likely NOT the same as your astrological sign, you will need to read more about precession.  Here are some useful resources and video simulations to help you.  Check one (or more!) out.  You might want to show it to your survey participants - if they are willing...:) 

Braganca, Pedro. (2007) Why Your Zodiac Sign And Horoscope Are Wrong. Live Science.

Griffin, Andrew. (2015) Astrological Sign Are Almost All Wrong, As Movement of Moon and Sun Throws Out Zodiac. The Independent. 

O Briain, Dara.(2015) Which Stars Were You Really Born Under. BBC Stargazing Live. BBC

Sanders, Steven (2013) Precession of the Earth. YouTube.

Because the Earth spins like a top on its rotation axis, creating day and night, AND because the Earth is not a perfectly spherical ball, our planet slowly "wobbles" like a top.  It takes 26,000 years to complete just one "wobble" - which means that over about that length of time, your sunsign would change through all 12 zodiac constellations.  If the current zodiac and associate calendar we use are about 2000 years old, you would be 2000/26,000 ~ 1/12th off - about one full sign.  So if you (or your participants) really like your sunsign, if you are reincarnated in 24,000 years, you'll have it again! :)  

Based on what you have read, or watched from the above list, what is your sense of the explanation about why your Sunsign might not actually be what you though?  Answer in a sentence or two at most - but if you do use outside resources or references, please do include citations for them. 

==> Remember to do this activity again with a friend, family member, or co-worker!  Record their answers to the questions above. Doing this alone is only part of the assignment.  Teaching others what you are learning is really the KEY element here!

Extra Credit:

Check out and evaluate one of the following in addition to the above.  Be sure to create a properly formatted citation, and quote or paraphrase something from the articles directly - and comment upon that quote or passage - to show your readers your scholarship.

Or, find another site and evaluate it! 

 1/17/19 - SH

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Questions/Comments? email me!

Skymap Online:

Here is an image using this online tool; you set the Time and Date at the top, then press "GO!".  Find the Sun (in the middle of the sky, and note the zodiac sign nearest to the Sun - that is the real "sunsign"! 

The image here was for someone born on October 25th.  They thought they were born under the sign of Libra, but you can see the Sun is still in front of the constellation of Virgo.











Neave Online Planetarium

This application clearly shows you the day and time, but won't ID the constellations.  You have to "know" that the zodiac sign near the Sun was "Leo", or move your mouse over one of the stars to see the label.

I've linked a secondary picture below taken when the mouse was over Leo's brightest star, Regulus, so show how the label will tell you the constellation.