Other Key Terms
Ephemeris
Astrology meaning, traditional reading, and frequently asked questions.
Quick Definition
A table or database of planetary positions for every day — the working reference of astrological calculation.
What Ephemeris Means
An ephemeris is a tabulated list of planetary positions for every day at a specified time (usually midnight or noon GMT). Astrologers use ephemerides to find planetary positions for any date in history. The most widely used printed ephemerides are the American Ephemeris (Neil F. Michelsen) and the Rosicrucian Ephemeris. Modern astrology has largely moved to digital ephemerides like the Swiss Ephemeris, which underlies most astrology software. Without ephemerides, astrology cannot calculate charts — they are the working reference of the field.
How to Spot Ephemeris in Your Chart
Ephemeris appears in birth-chart work as a feature of the chart’s underlying structure. Whether you spot it directly depends on your chart software — most modern programs surface this information clearly in the chart data panel.
Working with Ephemeris is mainly a matter of knowing it exists and what to look for. Once you recognise the concept, you start seeing it in every chart — and in transits, returns, and predictive work as it interacts with other themes across time.
Concrete Example
A traditional astrologer drawing up a natal chart for a client born in 1973 will consult the 20th-century ephemeris to find each planet’s position on the birth date.
What Ephemeris Traditionally Indicates
Ephemeris appears across both traditional and modern astrology as part of the working vocabulary of the craft. Different schools emphasise it differently, but the underlying concept is consistent enough that astrologers from different traditions can communicate clearly about it.
Understanding Ephemeris as part of a broader system matters more than memorising a single definition. Astrology is interlocking — every concept connects to several others — and Ephemeris earns its meaning from the role it plays in the whole. The related terms below are a good place to keep exploring.
Frequently Asked Questions
Is an ephemeris just for astrology?
No. Astronomers have used ephemerides since antiquity to track planetary motion. The astrological use is one application; ephemerides also serve navigation, astronomy, and orbital mechanics.
What is the Swiss Ephemeris?
The Swiss Ephemeris is a high-precision digital ephemeris released by Astrodienst, based on the JPL ephemeris from NASA. It is the calculation engine behind most modern astrology software and provides accurate planetary positions for the period 13201 BCE to 17191 CE.
Can I read my chart from an ephemeris alone?
An ephemeris gives you planetary positions, but you still need to calculate houses for a full natal chart, which requires the time and place of birth in addition to the date. Most astrologers use software that combines an ephemeris with house calculation.
How old is the practice of using ephemerides?
Babylonian astronomers compiled the earliest known ephemerides around the 7th century BCE. The tradition runs continuously from there through the Greek, Arabic, and European astronomers into modern computational astronomy and astrology.
Related Terms
Other glossary entries that connect to Ephemeris:
Transit
A planet’s current movement and the aspects it makes to your natal chart — the foundation of predictive astrology.
Ingress
A planet’s entry into a new zodiac sign — read as the start of a new chapter for that planet’s themes.
Retrograde
When a planet appears to move backward from Earth’s perspective — read as an inward, review-oriented phase.
See Ephemeris in Your Own Chart
Definitions are easier to internalise when you can see them in your own birth chart. Calculate yours free — it places every term on this page into the concrete geometry of your own life.