The foremost tool of astrology is the horoscope, a chart of planetary and other celestial positions at a certain time, as seen from a certain place. Where there is a time and a place, a horoscope chart can be made.
     The most common one, nowadays, is the birth chart, or nativity, based on the time and place of a person's birth. But horoscopes can be made for other things as well - countries, companies, projects, as long as a time and place can be established.
     There are four components of a horoscope:

1. The planets
2. The 12 Zodiac signs
3. The 12 Houses
4. The aspects

     Western astrology is clear on the number of Zodiac signs and Houses, but astrologers differ on how many planets and aspects to include in the horoscope. Still, there is consensus on which are the most important ones.
     In the horoscope chart, the above components are marked at their respective positions, as seen at the time and place of the horoscope in question. The perspective is geocentric, ie. as seen from earth - although the planetary movements are heliocentric, around the sun. What matters in astrology is how the sky looks from our viewpoint.
     There are many ways to design a chart. In Greece and in Europe, up until recent times, the most common way of drawing the horoscope chart was the so called envelope design, where each triangle of the figure represented an astrological House. See the horoscope of Martin Luther below.


Horoscope in envelope design of Martin Luther (1483-1546).
     Nowadays, the circular horoscope chart is used by most astrologers. In it, the outer circle marks the Zodiac, where each of the twelve Zodiac signs is 30° of the total 360° circle. They are placed in a counter-clock order. Inside of that circle, the positions of the planets are marked. Also, there is the twelve part division of the astrological Houses. The aspects between planets are marked with straight lines between them (in this case the lines of the innermost circle).
     Here is a modern style circular horoscope chart:


Circular horoscope chart.
     The ascendant, the Rising point in the east, should be at the left side of the horoscope, and the Medium Coeli somewhere on the top halft of the horoscope. That means the horoscope east is to the left, west to the right, south is up and north is down. The horizon is represented by a line from the Ascendant to the Descendant at the opposite side of the horoscope. So, what can be seen of the sky at the time and place of the horoscope, is only what is above that line.
     In astrology, the components above are interpreted in a combined way. A planet, its Zodiac sign, House and aspects - it's all brought together in the search for the specific meaning in the horoscope. That is not an easy task, and astrologers may come to different conclu­sions - although they agree on most of the basics.
     For more about the basics on the astrological com­ponents, see the links below.

© Stefan Stenudd, February 19, 2006
The planets
The Zodiac
The Houses
The aspects