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Astrology 101

Topics: Lifestyle & Culture | Add A CommentBy admin | February 15, 2011

Why I have at least as much faith in astrology as I do in say, economics, with a brief introduction to how it works.


One of history’s better known
astrologers, Galileo Galilei

People have on occasion asked me if I believe in astrology. I always have to chuckle a bit, because to me it’s sort of like asking if I “believe in” history, theoretical physics, archaeology, or economics. I’m referencing those four fields of study in particular, because I used to hang out with a group of doctorate students that included a person from each, and my favorite conversational goad was to ask them how their fiction writing was going. Using the historian as a wedge, it was pretty easy – especially after a few drinks – to get them all to admit that in the end, they were all really just fiction writers at heart, even if in the beginning they hard started with some reasonably solid facts. So do I “believe in” Astrology? Probably more than economics; I always considered the term Voodoo Economics to be redundant. But the simple answer is “no”. However, I find it to be a fascinating field of study. A field of study that – unfortunately – attracts a lot of loonies. And it seems that the looniest of the loonies are the ones who seek the most attention for their work, while the folks who do all the rigorous computation and statistical studies remain almost entirely unknown. The result of this is that the familiar face of astrology is the “daily horoscope”. Even the most uninformed student of the “serious” study of astrology will side up with the pragmatist who says that a daily horoscope is bunk, and at best a form of entertainment. This form of astrology supposes that somehow, all the people born in a given month (i.e., people with the same “sun sign”) will somehow have a similar theme playing out in their lives on a given day. We’re talking about more than 580 million people. I’d feel confident saying that about the only thing that ALL of these people would have in common is that they all benefit from breathing oxygen. I recently offered up a less-than-vigorous defense of the serious study of astrology, but just what is the “serious” study of astrology? I would say that it’s an attempt to explore the human psyche and its interconnectedness with the universe in which it dwells. And just how does it do this? Well, much like psychology, sociology, philosophy, and religion, it relies on a lot of symbols and analogies to describe the human experience, but astrology attempts to connect this human experience with observable planetary cycles. I know. Still probably sounds fishy. But I’m not trying to convince you of anything, other than to understand a little more about the topic before you dismiss it in relative ignorance. I mean, we’d all agree that alchemy was probably a frivolous pursuit, but modern chemistry and medicine would probably not exist if alchemy hadn’t. And according to that Wikipedia item just linked, Isaac Newton devoted more of his writing to it than his other studies combined. So let’s not throw out the proverbial baby with the proverbial bath water. If you’re still reading, below is my version of Astrology 101. Although I’ll be doing an Astrology 102, we probably won’t have a 200 series level; not only do I not have enough knowledge to pull it off, I don’t have enough interest either!

Geocentric Natal Charts

There are a multitude of approaches to drawing an astrological chart, but if you learn about astrology in the west, you will almost certainly learn geocentric astrology first, and use a natal chart. A useful natal chart will be based on a birth time accurate within minutes, because – among other things – the “rising sign” or ascendant will change about every two hours because of the Earth’s rotation. The fact that the geocentric chart has the Earth in the center doesn’t mean an astrologer is some kind of pre-Copernican numb-nut that doesn’t understand that the Earth revolves around the sun, in fact, a decent astrologer probably knows more about relative planetary and solar motion than even a fairly educated person who doesn’t specifically study astronomy or a related science. You might find it interesting to note, by the way, that 20% of Americans and a third of Russians surveyed think that the sun DOES revolve around the Earth. In any case, the image below is a typical natal chart, with some explanation of the gobbledygook:

Okay,  But How Does That Relate To Reality?

The fact that a geocentric chart places the Earth in the middle can be a little confusing even if you know how things are actually laid out in terms of the Earth in relation to the sun and the constellations of the zodiac . But the image below makes it a little easier to fathom. In a geocentric chart, the moon, the planets, and even the sun will appear to be in different zodiac signs from the vantage point of the Earth, depending on where the Earth is in its orbit. In the diagram below, if you were on the Earth that’s closer to you in the diagram, the sun would appear to be on the “cusp” of Libra and Virgo.

Planetary Aspects & Transits

That first chart above only indicated the apparent location of the planets in the constellations of the zodiac and the (rather arbitrary) twelve houses. Once you begin to dig a little deeper into the study of astrology, one of the first things that adds more nuance and specificity to an individual’s chart are planetary aspects. These are specific angular relationships between the apparent positions of chart elements at a specific time. The easier to grasp aspects include sextiles (60 degree relationships) squares (90 degree relationships) trines (120 degree relationships) oppositions (180 degree relationships) and conjunctions (when two objects are appear to be in the same location). In the chart below, sextiles and trines are blue, squares and oppositions are red.

So How Are All These Positions Determined?

You might be surprised at how much actual science is used to calculate a basic astrological chart. Many astrologers rely on the Swiss Ephemeris , which is largely based upon the DE406 ephemeris from NASA’s JPL. To get an idea of just how complicated this information really is, download and view an ephemeris in PDF from this page. When I learned how to do astrological charts, I actually referred to these tables for the basic information, and then had to perform a series of fairly basic algebraic equations to refine the positions based on exact time of birth. At that time, there was astrology software available, but it was insanely expensive. Lucky for you, all you have to do if you want to cast a perfectly accurate chart is visit Astro.com and create a free account!

So What The Heck Do You Do With All This Nonsense?

We’ll get to that in Astrology 102. If you want to play along, go ahead and create a free chart, and in the next piece we’ll walk you through the basic symbology and how to interpret a chart.