Mercury

Definition

Mercury is the smallest planet and the closest to the Sun, circling it in 88 days. From Earth it never strays more than 28 degrees from the Sun, and it goes retrograde — appearing to move backward — three or four times a year for about three weeks. Astrology gives it a home (domicile) in Gemini and Virgo, its strongest placement (exaltation) in Virgo, its weakest (fall) in Pisces, and difficult placements (detriment) in Sagittarius and Pisces. In the Hellenistic sect system, which sorts planets by day or night birth, Mercury alone is neutral.

In Tradition

Western astrologers read Mercury as the planet of communication: how you think, how you perceive, and how you make connections between ideas. Traditionally it is neither a benefic nor a malefic — neither an easy planet nor a difficult one — but neutral, tending to take on the character of whatever planets it aspects.

In Practice

Astrologers read Mercury's sign, house, and aspects (the angles it makes to other planets) for your communication style, how you learn, and how your mind works. Because Mercury never strays more than 28 degrees from the Sun, it always sits in the Sun's sign or one right beside it — which limits how many Sun-Mercury combinations are possible. Its retrograde periods matter in electional astrology, the art of choosing a good moment to begin: new ventures involving communication, contracts, or travel are traditionally avoided while Mercury is retrograde. Reading Mercurial themes fully reaches beyond the planet itself to include anything in Gemini and Virgo, anything in the third house, and the planet that rules the third house.

Historical Origin

Mercury's astrological meanings come from its classical link to the Greek god Hermes, messenger of the gods. Its traditional ties to communication, commerce, travel, and trickery all trace back to that mythological identification. Counting Mercury as the sole neutral planet in the sect system is a distinctive Hellenistic idea.

Further Reading

• Robert Hand, Horoscope Symbols
• Sue Tompkins, The Contemporary Astrologer's Handbook
• Steven Forrest, The Inner Sky