How Horoscopes Work

It's All in the Stars

12 Horoscope Signs
Image courtesy Skyscript

We have seen that astrology can be used for many different applications, but for this article, we will focus on Natal Astrology, or astrology based on the date of the subject's birth. What can an astrological reading tell us, and how is this information gleaned from a star chart?

An astrology reading begins with the date of birth of the subject. Sometimes, the exact time and location of the birth are considered as well.


We've already learned how to figure out a sun sign. Here is another look at the symbols:

The next step is to figure out what signs the planets are in. It's very similar to figuring out the sun sign -- in fact, the sun and the moon are called "planets" in astrology because they are treated much like the other planets, albeit with more importance. Here are the symbols for the planets:

Image courtesy Skyscript

Using mathematical models and scientific knowledge of the movements of the planets, it is possible to calculate the position of a planet in the sky for any date, although the further you get from the present, the more complicated it becomes.

Example chart showing the positions of the planets in relation to the signs for a given date

Each planet has its own aspects and influences, much like the signs. How the influence is exerted upon the subject depends on which sign the planet appears in, which other planets are present and if the planet is in retrograde motion.

Read more about each planet's traits at AstroStarCharts: Planets.

The positions of the planets relative to one another are important, as are various angles and mathematical calculations based on all of these factors.

Here's an example: Saturn often is often characterized by patience, discipline and a methodical nature. When Saturn is found in Sagittarius, a sign known for extroversion, confidence, a desire to explore and a disdain for rules and restrictions, some kind of interpretation of these two conflicting symbols is needed. Ten different astrologers will probably give you 10 different interpretations -- one possible version suggests that Sagittarius' exploration of universal truths combines with Saturn's patience and discipline to form a dogmatic belief in a particular system or idea (Burk, pg. 144).

The possible combinations and permutations of all these different factors approach infinity, which is why readings tend to vary so much from one astrologer to another, even if they use the same general astrological system.