The planets, explained

A chart is built from three kinds of thing, and the planets come first. If you want the plainest model, hold onto this: the planets are the what, the signs are the how, and the houses are the where. A planet is a drive, a part of you that wants something. The sign it sits in colours the way that drive is expressed, and the house it falls in names the part of life where it plays out. Venus is love and value in every chart; the sign says in what style you love, and the house says where you tend to find it.

Ten bodies do most of the work in a modern chart. Tradition counts the Sun and Moon among them. The word planet is older than the telescope and once meant any wandering light, so the two great lights kept their place in the company. Astrologers sort the ten into groups by speed, because speed tells you how personal a planet is and how long its influence lasts.

Why speed matters

Every planet is seen from Earth moving through the zodiac, but at very different rates. The Moon goes round in about four weeks. Pluto takes around two hundred and forty-eight years. That difference shapes how each one is read.

A fast planet changes sign often, so its position is specific to a small window of births. Two people born a week apart can have Venus in different signs. A slow planet stays in one sign for years, so everyone born in that stretch shares it. That is why the fast planets describe the personality you would recognise as your own, while the slowest describe the concerns of a generation, made personal by the house they fall in.

Speed matters when planets move over your chart, too. A fast planet passing over one of your placements is a matter of days. A slow one can take a year.

The personal planets

The Sun is identity: the core self you are growing toward, the part of you that feels most like yourself when life is going well. It spends about a month in each sign, which is why your birthday is usually enough to name your Sun sign. Its house shows where you most want to shine.

The Moon is the inner life: emotion, instinct, memory, and what you need in order to feel safe. It changes sign every two or three days, so your Moon sign needs at least your birth date and often your time. Where the Sun is who you are becoming, the Moon is how you actually feel your way through a day.

Mercury is the mind and the messenger: how you think, learn, speak and write, and how information moves through your life. Mercury never strays far from the Sun, so it is always in your Sun sign or one of the two signs beside it. That small range is one reason two people with the same Sun sign can think and speak so differently: one has Mercury in the Sun's own sign, the other in its neighbour.

Venus is love, pleasure and value: what you find beautiful, how you attract and relate, what you are willing to spend, and what you want in return. It also stays near the Sun, never more than two signs away.

Mars is drive: desire, courage, anger, competition, the energy that gets you out of the chair and moving toward what you want. Its sign describes how you pursue things and how you fight; its house shows where you spend the most effort.

The social planets

Jupiter and Saturn move more slowly, so they describe the wider arc of a life more than the weather of a week. They are the bridge between the personal planets and the generational ones, and they tend to show how you meet society, work and the world outside your own circle.

Jupiter is growth: opportunity, faith, generosity, learning and the direction a life opens and widens. It spends about a year in each sign and returns to its birth position roughly every twelve years. Its house often shows where luck and confidence come most easily, and also where you can overdo things.

Saturn is structure: discipline, responsibility, limits, time and earned mastery. It spends about two and a half years in a sign and takes close to twenty-nine years to go round, which is why its first return is such a recognisable threshold; see your Saturn return. Saturn's house is often where life asks for patience first and gives lasting results later.

The outer planets

Uranus, Neptune and Pluto were discovered with telescopes, the first in the eighteenth century, and they are so slow that each spends years in a single sign. Because a whole cohort is born under the same placement, they are read as generational as much as personal. What makes them yours is the house they fall in and the angles they make to your faster planets.

Uranus is awakening and disruption: independence, invention, the sudden break and the truth that will not stay quiet. It takes about eighty-four years to go round.

Neptune is dissolving and dreaming: imagination, compassion, spirituality, music and art, and the fog of confusion or idealism that can come with them. It takes about a hundred and sixty-five years.

Pluto is depth and transformation: power, intensity, and the cycles of ending and renewal that remake a life from the root. Astronomers reclassified Pluto as a dwarf planet, and astrology still reads it as a full member of the chart.

Retrograde planets

Every planet except the Sun and Moon appears, at regular intervals, to stop, move backward through the zodiac and then turn forward again. This is retrograde motion. No planet really reverses; it is an effect of watching moving bodies from a moving Earth.

The mechanics differ by planet. Mercury and Venus orbit inside Earth's orbit, and they turn retrograde as they pass between Earth and the Sun. Mercury does this three or four times a year for about three weeks, and Venus about every eighteen months for around six weeks. Mars and the planets beyond it orbit outside ours, and they turn retrograde when Earth overtakes them on the inside track, around the time they sit opposite the Sun in our sky. Mars does this about every two years; the slow outer planets spend several months of every year retrograde.

A planet that was retrograde when you were born is often read as a drive turned inward, worked out privately before it is expressed. The primer on Mercury retrograde explains the effect in more detail.

Rulers, dignity and the chart ruler

Every sign has a ruling planet, the planet most at home there. The Sun rules Leo and the Moon rules Cancer. Mercury rules Gemini and Virgo, Venus rules Taurus and Libra, Mars rules Aries, Jupiter rules Sagittarius and Saturn rules Capricorn. In traditional astrology Mars also ruled Scorpio, Saturn ruled Aquarius and Jupiter ruled Pisces; modern astrology gives those three signs to Pluto, Uranus and Neptune, and many astrologers use both.

This is why a planet in the sign it rules is said to be strong: its nature and the sign's nature agree. A planet in the sign opposite its home, such as Venus in Aries or Mars in Libra, has to work in a style that does not come naturally. Tradition also names signs where a planet is exalted, honoured as a guest: the Sun in Aries, the Moon in Taurus, Venus in Pisces. None of this makes a placement good or bad. It describes how much translation a drive needs.

The planet that rules your Rising sign has a special role. It is called the chart ruler, and its sign and house describe the direction of the whole life. If you have Virgo rising, Mercury is your chart ruler, and where Mercury sits becomes one of the most important details in your chart. Finding it needs your birth time, because the Rising sign does.

Beyond the ten

A reading also uses a few points that are not planets. The North and South Nodes are where the Moon's path crosses the Sun's and are read as direction and habit. Chiron, a small body between Saturn and Uranus, is read as a wound that becomes a teacher. Black Moon Lilith, a calculated point of the Moon's orbit, is read as what you were taught to hide. They add detail; the ten planets carry the story.

Where your planets fall

Knowing what each planet governs is the first half. The second half is personal: which sign each of your planets sits in, which of the twelve houses it lands in, and what angles it makes to the others. The same Mars acts differently in fire than in water, and differently again in the house of work than in the house of home. The three loudest placements, the Sun, the Moon and the Rising sign, carry much of who you are, but the whole cast is what makes a chart particular. Take two people with Venus in different places. One has Venus in Taurus in the seventh house: love is loyal, physical and slow to start, and it gathers around a committed partner. The other has Venus in Aquarius in the eleventh house: love begins in friendship, wants plenty of room and often grows out of a shared cause or circle. Both value love deeply. They simply look for it in different rooms and give it in different styles, and neither would recognise their own heart in the other's description.

When you are ready, see your own birth chart and read where each planet stood when you were born.