Refer to the Astrology Chart below as you read these descriptions; feel welcome to print the chart for ease of reference (right-click on the chart). The Astrological system taught here is the Tropical Zodiac, mainly used in western astrology. The Sidereal Zodiac, is used in Vedic (Hindu) Astrology.

The general concept of an astrological chart is to plot the solar system, as seen from your perspective, onto a piece of paper. An astrology chart is a 360 degree circle which represents the celestial ecliptic, with a ring of zodiac constellations arranged around the outside; planet positions are marked within this circle. The entire circle is divided into 12 segments called Houses. Basically, we refer to the chart to calculate the angular relationships planets have to each other, and to sensitive points of the chart - the cardinal points. More detail below... 

The Ascendant: Looking at the chart - to your left at 9 o'clock is the Eastern horizon, this point is known as the Ascendant (AC) of the chart. The AC represents the degree of the zodiac sign that was aligned with the eastern horizon at the time of the chart. The AC marks the beginning of the first house. On this chart the AC is 15 Gemini 43.

The Descendant: Looking at the chart - to your right at 3 o'clock is the Western Horizon, this point is known as the Descendant (DC) of the chart. The DC represents the degree of the zodiac sign that was aligned with the western horizon at the local time of the chart. The DC marks the beginning of the seventh house. On this chart it is 15 Sagittarius 43.

There are 12 Houses in the system we are examining. The Houses are numbered in an anti-clockwise direction.  From the Ascendant to the Descendant, the lower hemisphere Houses are numbered 1, 2, 3, 4, 5, and 6; and from the Descendant to the Ascendant, the upper hemisphere Houses are numbered 7, 8, 9, 10, 11 and 12.

The 12 Houses are symbolically divided into 4 elements Fire, Earth, Air and Water representing elements of human experience; Spiritual, Physical, Intellectual and Psychological. Each of these elements has 3 different modes of expression; Cardinal, Fixed and Mutable representing modes of human expression; Initiating, Developing and Adapting. This element and mode symbolism has a base relationship to the natural tendencies of each zodiac sign...listed in brackets. This table lists the element and mode of the Houses, regarded as arenas of experience. Check The Astrologers Handbook by Sakoian & Acker in the bookshop for more on this topic.

At extreme latitudes (near the arctic and antarctic circles), some Houses will span three zodiac signs due to the exaggerated curvature of the planet. On the example chart below, the 3rd House spans three zodiac signs, Leo, Virgo and Libra. The beginning of the 3rd House is 25Leo32; the end of the 3rd House (and simultaneously the beginning of the 4th House) is 00Libra51.  On this example chart, the sign of Virgo is called an "intercepted" sign because it is completely contained within the 3rd House. So interpretation of the 3rd House would require consideration of the condition of the planetary "rulers" of all three zodiac signs, the Sun ruling Leo, Mercury ruling Virgo and Venus ruling Libra.

The colourful lines through the centre of the chart highlight an aspect between two positions. Aspects measure the distance around the circle between two planets or points. The chart circle is 360 degrees around the circumference. The example chart shows Venus is opposite (180 degrees) to Uranus; and the Sun is sextile (60 degrees) to Mars.  A small orb of influence is allowed either side of the exact aspect...so if two planets are perhaps 184 or 176 degrees apart, I'll still call that an opposition. More will be offered on Aspects as a separate topic.