Ephemeris

Definition

An ephemeris is a reference table that lists the calculated positions of celestial bodies at regular intervals, usually for each day at a specified time and time zone. Astrological ephemerides commonly include the Sun, Moon, planets, lunar nodes, and other points, along with details such as retrograde motion and sign changes.

Astrological Meaning

Astrologers use an ephemeris to determine where planets were positioned on a birth date or where they will be during a future period. It supports natal chart calculation, transit work, electional astrology, and historical research. Unlike a horoscope, an ephemeris does not interpret planetary positions; it provides the astronomical data from which interpretations are developed. Readers must account for the listed time, time zone, and daily planetary motion when estimating an exact position.

Why It Matters

Before astrology software became widespread, the ephemeris was an essential chart-calculation tool. It remains useful for checking digital results and observing planetary cycles at a glance. By scanning its tables, an astrologer can identify retrograde periods, ingresses, conjunctions, and broader patterns without calculating a complete chart. Accurate use helps separate reliable planetary data from the interpretive judgments applied afterward.

Related Encyclopedia Entries

• Traditional Astrology
• Astrological Terminology
• Natal Chart