The Anatomy of
Your Birth Chart

Every birth chart is an astrological map, in the shape of a wheel.

For example:


Get your chart handy.

While I’ve included my chart here for reference, I recommend printing your own chart and having it with you as you read through this section. While reading the descriptions below, take the time to locate everything that I’m describing within your own chart.

If you don’t already have your chart, return to Step 1.


The Whole Wheel = The Sky Itself

Your chart is a map of the sky, and every piece of it represents something you would see if you were looking up — the stars, the sun, the moon, planets, asteroids, and all of the lines our geometrically-inclined minds observe between them.


The Rim of the Wheel = The Path of the Ecliptic & the Stars

The path of the ecliptic is an invisible line in the sky that marks the path of the sun (as seen from Earth) over the course of one year.

The zodiac signs are named after the constellations of stars that appear along this path, and on the outside of the wheel — in the creamy border — you will find the symbols for the 12 zodiac signs. These are the big glyphs in green, red, blue, and orange.

Time and time again, articles come out claiming that the zodiac signs are wrong because there are technically thirteen constellations along the path of the ecliptic. Also, the stars are always moving, so where they are today is not where they were when this mapping system was created. (And in Vedic astrology, the constellations are updated to match the physical location of the stars.)

However, in western astrology, none of this matters. Because while the signs were first inspired by the literal stars, they’ve since come to mean something else.

When you say that a planet is in a certain sign, what you’re really saying is where (approximately) the planet is in the sky. In other words, the zodiac is a means of breaking up the sky and using the “signs” as guideposts, like flags on a trail.

The flags were laid long ago to help us make sense of the movement of the planets, and regardless of where the stars were then and where they are now, the flags remain firmly planted, separating the path of the ecliptic into twelve equal sections that let us compare and contrast the positions of planets over time.

Think about it: if we were constantly updating the zodiac to match the position of the literal stars, then when we looked at a map from 1000 AD and today, we wouldn’t be able to know where the planets actually were. Say the sun was in Cancer in both the old map and the new map. If “Cancer” is always in the same place, then we can know that the sun is currently close to where it was then, but if “Cancer” is an always-changing target, then we’d have no way of quickly and easily comparing past planetary positions with current and future planetary positions. The maps of today would have basically no astronomical relation to the maps of the past. Instead, they would be rooted in fleeting alignments of moving stars rather than anchored into the path of the ecliptic.

Put simply: In western astrology, the zodiac is (above all else) a mapping system designed to help us accurately understand the position of the planets in the sky. And astrology itself is the practice of divining information based on the relative position of the planets along the path of the sun.

The path of the sun is broken into twelve equal zodiac signs, and then, each sign is broken into 30 degrees. (30x12=360 degrees…as in, the degrees of a circle and almost the exact number of days in one year…aka the amount of time it takes the earth to orbit the sun and for the sun to travel along the path of the ecliptic.)

Each degree is marked by the little black lines circling the wheel. The black lines are a bit longer to mark every five and ten degrees.

Counting degrees becomes important when determining the positions of planets and also the aspects between planets and transits. More to come on all of this in later sections, but that’s enough for now.


The Spokes of the Wheel = The Houses

Within the wheel, just inside the zodiac symbols, you'll see twelve curved blue rectangular boxes. These are numbered 1–12 in the upper left-hand corner, and they are called the houses.

Black lines (spokes) separate each of the houses, and determine how large each house is. This is different for each person and helps illuminate areas of particular influence in a person’s life. For example, in my chart, you’ll notice that my 1st house is significantly larger than my 12th.

(Note: Some astrologers (e.g., Chani Nicholas) practice something called Whole Sign astrology in which they keep the houses the same size, but since this eliminates a layer of nuance from a chart, I don’t like to do that. The name for the house system I use is called Placidus.)

Of the twelve black lines separating the houses, four of these are thicker and darker. They are labeled just outside the wheel. If you’re reading them counter-clockwise from the left, they go: AC, IC, DC, MC. These lines are powerful points in your chart.

  • The AC (also known as the ascendant or rising) marks the start of the 1st house. It’s a powerful indicator of your external self and how you are perceived.

  • The IC (the imum coeli — Latin for “bottom of the sky”) marks the start of the 4th house and represents your roots, your subconscious, the past, and the parts of you that you’ve maybe buried so deep you’ve forgotten all about them.

  • The DC (the descendant) marks the start of the 7th house and is the most powerful point in the house of marriage. (Fun Fact: My husband proposed as the north node of the moon — aka the destiny point — was in the exact same spot as my DC! He, of course, had no idea about this. It was a total cosmic “coincidence.”)

  • The MC (the midheaven) marks the start of the 10th house and is a powerful point for your career.


The Hub of the Wheel = The Aspects

At the center of the wheel, in the large circular, creamy center, you’ll see a bunch of lines: red, blue, and the occasional green. These are the aspects, a.k.a. the geometric angles observed between planetary bodies.

When you’re first getting started, don’t worry about these.

More on this later.


The Rocks in the Wheel = The Planets

Within the houses, you'll see black glyphs. Each of these glyphs represents the sun, the moon, a planet, a calculated astronomical point, or an asteroid. You'll see the name for what planet and/or point the glyph corresponds to in the box to the left of the wheel. This is your map’s legend.

Beneath this legend, you’ll see a second box. This box has three columns labeled C, F, and M, and four rows labeled F, A, E, and W. This is another way of seeing where the planets are in your chart.

Inside this table, the planets are organized by the zodiac sign in which they are located based on the qualities of the sign.

C, F, and M represent the three modes of the zodiac: Cardinal, Fixed, and Mutable.

F, A, E, and W represent the four elements of the zodiac: Fire, Air, Earth, and Water.

Each of the 12 signs has a mode and an element associated with it (detailed in the signs section of this guide), so by looking at this table and seeing a glyph in a certain position (in association with an element and mode), you will know where to find it on the map (e.g., the moon in my chart is under A and M, so I know I’ll find it in Gemini).


Now that you know the parts of the map, you can start diving into what all of these parts mean and how to understand them.


Previous
Previous

Step 1: Get Your Chart

Next
Next

Step 3: The 12 Archetypes