Astrocartography

A map of where each planet was on one of the four angles — rising, setting, culminating, or on the lower meridian — at the moment of your birth, drawn as lines across the globe.

Astrocartography (also called astro*carto*graphy or locational astrology) projects a birth chart onto the world map. For each planet, there are places on Earth where — at the exact moment of birth — it was on the eastern horizon (rising, the ASC line), the western horizon (setting, the DESC line), directly overhead (culminating, the MC line), or on the lower meridian (the IC line). Joining those places traces four lines per planet across the globe. The lines are computed from ordinary spherical astronomy: the planet's right ascension and declination and the sidereal time at birth. A meridian (MC/IC) line is a line of longitude; the horizon (ASC/DESC) lines are curves that bend with latitude. Because the sidereal time changes about 15° an hour, the map depends heavily on the exact birth time. The tradition holds that living or travelling near a planet's line emphasizes that planet's themes in that place. That interpretive layer is the system's own; the geometry — where the lines fall — is exact and checkable.

Not: Astrocartography is not a guarantee that a place will be good or bad for you, and not a substitute for the practical realities of a location. It is a symbolic map layered on real astronomy. Without an accurate birth time the lines shift substantially, so it is only as good as the birth data.

The lines are computed exactly, but they depend on the birth time (~15° of longitude per hour of uncertainty). The meanings attached to standing on a line are interpretive tradition, not a demonstrated effect.