← Encyclopedia of Astrology · lesson 26/235
Planets
What a planet is
The word comes from the Greek planētēs, "wanderer". To the ancient sky-watchers the stars kept their places night after night, while a handful of lights moved among them — so those were the wanderers. Astrology still uses the word in that old sense: the Sun and the Moon count as planets, alongside Mercury, Venus, Mars, Jupiter and Saturn, because what matters is that they move through the zodiac, not what astronomy calls them.
In a chart each planet stands for one kind of drive, need or capacity: the Sun for vitality and purpose, the Moon for feeling and the body's rhythms, Mercury for thought and speech, Venus for attraction and pleasure, Mars for drive and conflict, Jupiter for growth and meaning, Saturn for limits and endurance. Dane Rudhyar put the modern view well: a planet is less a fixed character than a function with a meaning inside the whole chart.
A useful shorthand: the planet is what is acting, the sign is how it tends to act, and the house is where in life it acts. The aspects say how the planets talk to one another.
The classical seven and the modern three
For most of astrology's history there were seven planets, the ones visible to the naked eye. Lilly lists them in the old order of the spheres, slowest and highest first — Saturn, Jupiter, Mars, the Sun, Venus, Mercury, the Moon — and that same sequence, the Chaldean order, runs the planetary hours and the faces of the signs. Each of the seven rules one or two signs (rulership), and the whole system of essential dignity is built on them.
Three more were discovered with the telescope: Uranus in 1781, Neptune in 1846 and Pluto in 1930. Modern astrology reads them as the outer planets — slow, generational, tied to change on a large scale — and many astrologers give them a share in the rule of Aquarius, Pisces and Scorpio. Traditional astrology works with the seven alone and treats the outer three as additions.
Kinds of planet
The planets are grouped in several overlapping ways, each with its own entry:
- the two luminaries, the Sun and the Moon;
- the personal planets, fast-moving and closest to everyday character;
- the social planets, Jupiter and Saturn;
- the outer planets, Uranus, Neptune and Pluto;
- in the tradition, the benefics and malefics — Ptolemy's account of which natures help and which strain — and the day and night sect.
None of these makes a planet good or bad in itself. Each describes a nature that a chart can express well or with difficulty.
The Planets table
The Planets table of a chart lists each body with:
- its sign and degree — where it stands in the zodiac;
- its declination, when shown — how far north or south of the celestial equator it is;
- its house;
- its speed — how far it moves in a day, negative when it is retrograde;
- an R when it is retrograde;
- and, on charts that carry it, its weight — how strongly it features in this chart (prominence).
The table also lists points that are not planets — the lunar nodes, Chiron and Lilith — because they are read alongside the planets. They have speeds and signs like the planets, but no weight: they hold no dignity and rule no sign.