Mars lines
The four lines on your map where Mars was on an angle when you were born: overhead, underfoot, rising and setting.
Mars in astrocartography
Mars stands for effort: nerve, appetite, temper, competition, the urge to start something and have it done before lunch. The old texts called it the lesser malefic, hot and dry, and most people come to their Mars lines a little warily. Each of the four puts that heat somewhere different. On the MC it goes into work and ambition, on the IC into the house and the family, on the Ascendant into your body and the way you come at things, and on the Descendant into partners, rivals and anyone you deal with one to one.
A Mars line is hard in the plain sense: things take effort, tempers run shorter and rest comes last. That's also why some people pick one on purpose, athletes and founders especially, or anyone with a hard year of work in front of them. Read Mars in your natal chart before you judge the line. Mars in Aries, Scorpio or Capricorn counts as strong, Mars in Libra, Taurus or Cancer as weaker, and traditional astrologers add sect: for anyone born at night, with the Sun below the horizon, Mars is the milder of the two malefics.
Mars MC line: drive and competition
Mars overhead gives your work edge and speed. You get things done, win competitions, and are known as someone who pushes.
Mars IC line: a restless base
With Mars beneath you, home is where the energy goes. Renovation, physical work, arguments and strong family dynamics all tend to intensify.
Mars ASC line: courage and impatience
Mars rising makes you bolder, fitter and quicker to act, and others experience you as forceful. It is a strong line for training, taking initiative and recovering vitality.
Mars DSC line: fierce relationships
Mars setting brings dynamic, passionate and sometimes combative partners. Relationships here are intense and physical, with heat in both love and quarrels.
Where the lines run
Mars's declination, how far north or south of the celestial equator it sits, decides where its rising and setting lines stop: at 90° of latitude minus the declination. For births between 1930 and 2025 it ran from 28.7° S to 27.2° N, so in some charts those lines end as close to the equator as about 61° of latitude, north or south. Beyond that point Mars didn't rise or set at all on the day you were born, while the MC and IC lines carry on to the poles.
Mars lines are drawn with Pro; the free map shows the Sun, Moon, Venus and Jupiter.