Astrological charts
What they are and how they’re interpreted
What is an astrological chart?
First, it helps to know that astrology uses a geocentric framework: earth stands at the center of the perceivable cosmos, and as the sky revolves every twenty-four hours, the Sun, Moon, and five visible planets appear to move on a circular path around the earth.
An astrological chart is effectively a map reflecting the positions of the planets as observed from earth, a snapshot of the sky at a particular moment and place.
The sky’s quadrants
To create a map of any kind, we need to establish coordinates from two axes. In astrology, we adopt coordinates by halving the sky twice, first horizontally and then vertically.
The first halving follows the horizon, distinguishing what’s visible above us from what’s concealed below. The ascendant marks the point where planets rise against the horizon; the descendant marks the point where planets set.
The second halving of the sky distinguishes between the celestial bodies rising higher in the east and those descending or setting in the west. The midheaven marks the point where the Sun reaches its zenith (or highest point) each day around local noon. The lower midheaven, or IC, is its opposite under the earth, where the Sun reaches its nadir (or lowest point).
Houses: earth’s rotational impression
This local horizon still, courtesy of Stellarium software, shows the sky on 6 August 2023 at 10:00am EDT in Brooklyn, NY. At a high level, this video shows how the visual of the local horizon is mapped onto an astrological chart. Note that the midheaven is always found at right angles to the horizon, and that these two axes create four quadrants in our sky (two above the horizon, shown, and two below the horizon, not shown). The intermediate house cusps are trisections of each quadrant (not drawn exactly to scale in the video demonstration).
As the earth rotates on its axis, the planets rise and move from east to west. Starting at the ascendant, the sky is divided into twelve segments which astrologers call houses. The houses are numbered in such a way that they tell you which planets are next to rise over the ascendant: planets in the 1st house are first to rise, those in the 2nd house second to rise, etc. The earth’s rotation carries the Sun, the Moon, and five visible planets through the twelve houses in a 24-hour period.
Each of the twelve houses relates to specific life themes based on where it is in the sky. Is it in the east (where planets rise), or in the west (where planets set)? Is the house above the earth or below?, etc. Here’s a simplified example of how this works:
- The 1st house, or ascendant symbolizes life, birth, and new beginnings, marking the point where the Sun first emerges over the horizon. This house describes those who initiate and bring things into being. In a birth chart, the 1st house describes the person born; in a horary chart, it describes the questioner.
- The 10th house, or midheaven represents achievement, success, and glory, as this place marks the highest point of the Sun’s daily arc in our skies. In a nativity, this house shows the public acclaim one is accorded throughout life, and one’s vocation. In a horary chart, it indicates success of the thing being asked about, and whether it is profitable.
Archetypes in the sky
Individually, the planets embody primal archetypes and carry universal themes. We call these a planet’s significations. Through archetypal or historical association, planets come to signify a great number of things, both personal and impersonal:
- The Sun: fathers, kings, hunters; gold; ginger; magnificent rooms.
- The Moon: mothers, populace, gatherers; silver; onions; roads and highways.
- Mercury: scribes, tricksters, children; multi-colored gemstones; walnuts; markets.
- Venus: lovers, musicians, jewelers; lapis lazuli; apples; beds.
- Mars: soldiers, surgeons, smiths; iron; garlic; sources of heat.
- Jupiter: judges, philosophers, benefactors; sapphires; strawberries; courthouses.
- Saturn: elders, hermits, farmers; lead; cumin; mountains.
Astrologers expect a planet to manifest its significations in the area of life described by the house it occupies. Example: Saturn in the 10th house of career in a birth chart might point to working alongside, or for, elderly persons. If Venus was placed there instead, that might instead signify a career in luxuries, the arts, or hint at romantic entanglements in the workplace.
Contacts between the planets
Planets orbit the Sun in an objective sense. But, from our vantage point, they appear to orbit the earth, following the same path the Sun takes. That path is called the ecliptic; it is fixed in our sky and, behind it, we find a circle of twelve constellations after which the zodiac signs were named.
Sometimes planets form shapes with one another as they move about the zodiacal circle. When this happens, we say they aspect one another, which simply means the two planets begin to interact in a way hinted at by the shape they inscribe. The spatial arrangements of planets, or the shapes they inscribe in the zodiac encircling the earth, guide the astrologer in interpretation.
For example – when two planets are positioned a third of the zodiacal circle (or 120°) apart from each other, they form one side of a triangle. That shape is associated with harmony and stability in Western philosophy. By creating one leg of a triangle, these planets assert an intention of flowing, cooperative engagement between the two parties they represent.
As a counter example – when two planets are 90° apart, they form one leg of a square. Squares are associated with stability, firmness, and immobility in Western philosophy, and these qualities tend to produce friction and frustration. The nature of the planets involved, and the qualities of the houses they are positioned in, helps the astrologer determine how best to frame constructive, rather than destructive, tension between the parties described.
Planets can form a hexagon (60° apart, considered moderately helpful), a square (90° apart, tense and frustrating), or a triangle (120° apart, expediting and supportive). They may also be found aligned with one another (0° apart, significations merged like striking two bells simultaneously), or opposite one another (180° apart, open conflict). They can be measured in an astrological chart by degree, but many astrologers learn to spot them on sight.
