The GuideThe Words of the Chart

You do not need any of these words to have your own chart read — the book does that for you, in plain language. But astrology has a small, precise vocabulary, and once you know it the chart stops looking like a diagram and starts reading like a sentence. What follows are the terms you will actually meet, grouped by what they describe: the frame, the three layers a chart is built from, its angles, the relationships between its parts, and the words for how it all moves.

The frame

Zodiac — the band of sky the Sun, Moon and planets appear to travel through, divided into twelve equal thirty-degree signs. The word is Greek for "circle of little animals." Natal chart (or birth chart) — a map of exactly where every body stood in that band at the moment and place of a birth; natal simply means "of the birth." Ephemeris — the astronomer's table of where each planet is on every date, the raw data a chart is calculated from. Tropical zodiac — the system used across the Western world, which fixes the start of Aries to the spring equinox rather than to the present-day constellations; it is why your sign is measured from the seasons, not the stars behind them.

The three layers

A chart is built from three kinds of thing, and holding them apart is most of the battle. Planet — a moving body, the what: the Sun, the Moon and the eight wanderers, each governing an office of life (see the planets). Sign — one of the twelve thirty-degree temperaments, the manner or tone a planet acts through. House — one of twelve divisions of a single sky over one birthplace, the where: the area of life — self, money, love, work, home, vocation — a placement plays out in (see the houses). A single placement is really a small sentence: this planet, in this sign, in this house.

The angles and points

Ascendant, or rising sign — the exact degree of the zodiac climbing the eastern horizon at the birth minute; it opens the chart and sets where every house begins (see the rising sign). Descendant — the point opposite it, sinking in the west, traditionally the sign of partnership. Midheaven (or MC, from the Latin medium coeli, "middle of the sky") — the highest point of the chart, read for vocation and public standing; its opposite, the IC, for home and roots. These four are the chart's angles, and because the sky turns a full degree every four minutes, they are the parts that most depend on an exact time. The nodes of the Moon — two points where the Moon's path crosses the Sun's, read as a line of what is familiar and what is being grown toward.

The relationships — aspects

Aspect — the angle between two planets, and so the relationship between them; aspects are what turn a list of placements into a conversation. The five classical ones: conjunction (0°, two planets fused, acting as one), opposition (180°, a face-off and a balancing), trine (120°, easy, flowing support), square (90°, friction that forces growth) and sextile (60°, a gentle opportunity). Orb — the margin of degrees still counted as an aspect; a trine a few degrees off exact is still a trine, only quieter. Broadly, trines and sextiles are read as ease, squares and oppositions as tension — though the tense aspects are often where a life's real work and strength are found.

Dignity — a planet at home or away

The old astrologers rated how comfortably a planet sits in a given sign. Rulership (or domicile) — the sign or signs a planet governs and is strongest in, as the Sun rules Leo or the Moon rules Cancer; the ruler of your rising sign is called the chart ruler and given special weight. Exaltation — a sign where a planet is honoured and works especially well, though it is not its home. Detriment — the sign opposite its rulership, where it is least at ease. Fall — the sign opposite its exaltation, where its expression is hardest. None of these is a verdict of good or bad; they are notes on how freely a planet gets to be itself.

How it all moves

The natal chart is a single frozen moment, but the sky keeps turning, and several words describe that motion. Transit — where a planet is now, and the aspect it is making to your birth chart today; transits are how astrology speaks about timing. Return — when a planet comes back to the exact spot it held at your birth; the Saturn return near ages 29 and 58, and the yearly solar return on your birthday, are the best known. Retrograde — the illusion, from Earth, of a planet moving backward through the zodiac for a season; nothing truly reverses, but the period is read as a turning-inward of that planet's affairs. Lunation — the Moon's cycle, its new and full phases, the smallest and most frequent hand on the sky's clock.

Two more you'll meet

Element and modality — the two oldest keys to the signs: the four elements (fire, earth, air, water) for temperament, and the three modalities (cardinal, fixed, mutable) for the way that temperament moves (see the elements and modalities). House system — there is more than one way to slice the twelve houses from a sky; the two you'll hear named are whole-sign (each sign is one whole house, the oldest method) and Placidus (houses of unequal size timed to the horizon, the most common modern one). Reasonable astrologers differ; the difference mostly moves a few placements by one house.