Mars

Definition

Mars in astrology is the planet of drive, conflict and courage, and one of the two traditional malefics. Ptolemy made it chiefly drying and burning, which he explained by its fiery colour and its nearness to the Sun. Modern astrologers read its sign and house for how a person acts, competes and handles anger.

Primary source

The nature of Mars is chiefly to dry and to burn, in conformity with his fiery colour and by reason of his nearness to the sun, for the sun's sphere lies just below him.

— Ptolemy, Tetrabiblos I.4, Of the Power of the Planets, trans. F. E. Robbins (Loeb Classical Library 435, Harvard University Press, 1940). Open-access copy

Deep Understanding

The Greeks called the planet Pyroeis, "the fiery", for its reddish light, and gave it to Ares, the god of war, whom the Romans called Mars. Ptolemy turned the colour into physics. He places the sphere of Mars just above the Sun's, so the planet is dry and burning, and he reports that the ancients counted it with Saturn among the maleficent planets: Saturn for its excess of cold, Mars for its excess of dryness.

His scheme then works to temper that excess. He calls Mars masculine, and he explains why the tradition assigned it to the night: the dry planet was joined to the moist sect so that the moisture of the night would bring it into proportion, just as cold Saturn was given to the warmth of the day. He gives Mars Aries and Scorpio as its houses, which stand in square to the houses of the Sun and Moon to suit what he calls its destructive and inharmonious quality, and Capricorn as its exaltation, the sign where it reaches farthest south.

Gnostic readers counted Mars among the seven planetary spheres of the hebdomad, each held by a ruler the soul must pass on its way out of the world. The modern tradition reads the natal Mars for energy, desire and assertion, and its aspects for where effort meets resistance. Its retrograde periods, which come about every two years, are watched in the same way as those of Mercury.

Often confused with

Archon: in Gnostic cosmology a ruler set over one of the seven spheres, where Mars is the planet itself and its place in a chart. Saturn: the other traditional malefic, cold where Mars is dry, and given to the day where Mars is given to the night.

In Practice

Mars is easiest to find near opposition, about every two years, when it rises at sunset and shines red all night. Look for it then and set its colour beside the white of the stars around it. That colour is the first thing Ptolemy used to explain its nature.

Stefan's Alkimia. (2026, September 30). Mars. Pleroma Guide. https://pleroma.guide/en/lexicon/mars

Stefan's Alkimia. “Mars.” Pleroma Guide, 30 Sept. 2026, pleroma.guide/en/lexicon/mars.

Stefan's Alkimia. “Mars.” Pleroma Guide. September 30, 2026. https://pleroma.guide/en/lexicon/mars.

@online{alkimia2026mars,
  author = {{Stefan's Alkimia}},
  title = {{Mars}},
  organization = {{Pleroma Guide}},
  date = {2026-09-30},
  year = {2026},
  url = {https://pleroma.guide/en/lexicon/mars},
  langid = {english}
}