← Encyclopedia of Astrology · lesson 38/235
Personal planets
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What they are
The personal planets are Mercury, Venus and Mars. Many astrologers include the Sun and the Moon in the group as well; others keep the two luminaries in a class of their own and use "personal" for the three planets alone. Either way, the idea is the same: these are the fast movers, and because they change sign quickly, they differ from one person to the next even among people born in the same month or year.
The label is modern. It belongs to the twentieth-century sorting of the planets into personal, social and outer groups, which follows simply from how fast each one moves.
Why "personal"
Speed is the reason. Roughly:
| Planet | Time round the zodiac | Typical time in a sign |
|---|---|---|
| Mercury | about a year (as seen from Earth) | two weeks to two months |
| Venus | about a year | four to five weeks (up to four months) |
| Mars | about two years | six to seven weeks (up to seven months) |
The longer stays happen when a planet turns retrograde inside a sign. Mercury and Venus never stray far from the Sun — Mercury no more than about 28°, Venus about 47° — so they are usually in the Sun's sign or one of its neighbours.
Because they move quickly, their placement by sign, house and aspect is specific to the individual. Someone's Mars sign can differ from a sibling's born two years apart; their Pluto sign almost certainly will not.
How they are read
- Mercury — thinking, speaking, learning, the way a person takes in and passes on information.
- Venus — affection, taste, pleasure, what a person values and how they draw others near.
- Mars — drive, courage, desire, anger, and how a person goes after what they want.
With the Sun (purpose) and the Moon (needs), these are read as the everyday working parts of the personality: what a person notices, enjoys and pushes for. They are also the planets most often brought out in synastry, where one person's Venus or Mars touching another's personal planets is traditionally read as attraction or friction felt close up.
In transit, the opposite holds. The personal planets move so quickly that their transits are brief — Mercury or Venus crossing a natal point is a matter of a day or two, Mars a few days — and are usually read as colour or triggers rather than chapters of life. Their stations and retrogrades, when they linger, are the exception.
In the tradition
Older astrology did not use the word "personal", but it noticed the same speed. Mercury, Venus and the Moon were the inferior planets (those inside the Sun's sphere in the old order), and Mars, Jupiter and Saturn the superior ones. The tradition also judged them by nature rather than by speed: Venus the lesser benefic, Mars the lesser malefic, and Mercury changeable, taking on the nature of whatever it joins. Those gradings sit alongside the modern grouping rather than against it.