An ephemeris is a table of planetary positions by date. Astrolium's ephemeris covers every day from 1800 to 2400 — every row is a day, every column is a planet. Astrologers use ephemerides to track where planets are, when they change signs, and which periods involve retrograde motion.
How to read the table
Each planet cell shows a sign glyph and a degree. "♉27°" means the planet is at 27 degrees Taurus. When a planet crosses into a new sign, the degree resets to 0. That crossing is a sign ingress, and this table marks it with a colored badge at the top of the cell.
An Rx badge means the planet is retrograde — appearing to move backward from Earth's perspective. Hover over any cell to see the full sign name, exact degree, and daily speed in degrees.
Sign ingresses
When a planet moves from one sign to the next, the quality of its expression shifts. The Moon ingresses most often, changing signs every 2–3 days. Ingresses appear as colored badges at the top of the cell. The badge shows the sign name and glyph.
Slower planets hold a sign for months or years, so their ingresses carry more weight. Jupiter spends roughly a year per sign. Saturn takes two to three years. When Saturn or Jupiter ingresses, it marks a structural shift in collective themes — one that practitioners track carefully for client work.
How astrologers use this
Client prep. Before a session, knowing which transits are active tells you what the client may be navigating. Pull up the month, find the row for the appointment date, check which planets are in sensitive positions or entering new signs that week.
Electional work. Picking a date to sign a contract, launch a project, or schedule a surgery means reading the sky first. The table shows which dates have Mercury retrograde, which days Venus changes signs, and when the Moon is in a favorable position.
Timing decisions. Outer planets move slowly. If Saturn holds 18° Pisces for most of a month, that transit's pressure holds steady all month. Hover over any cell to see the exact daily speed.
Learning to read aspects. When two planets share the same sign and close degrees across several rows, a conjunction is forming. The ephemeris is the raw data behind that observation — you can track aspects visually before running calculations.
The graphic ephemeris, inside the app
A table tells you where a planet is. A graphic ephemeris tells you when two things meet, which is a different question and a faster one to answer visually. The Astrolium workspace carries one, folded into the ephemeris table and into Dials, collapsed until you ask for it.
It is the Ebertin form: pick a modulus of 360, 90, 45, or 30 degrees, pick a window from 1 to 36 months, and read the crossings. Natal points render as horizontal lines; transiting bodies render as curves that walk down the page. Where a curve crosses a line, that contact is exact. On the 90 degree view the Cardinal, Fixed, and Mutable bands are labelled.
The panel is unusually honest about what it cannot do, and the disclosure sits right there rather than in a help article:
- The window always starts today. There is no earlier start date, so it cannot review a year that has already happened.
- It draws the same 11 bodies every time: Sun, Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto, the Mean Node, and Chiron. Show Moon adds a twelfth, and needs a window of 3 months or less. Your own enabled point set, node model, and zodiac do not reach this chart.
- There are no natal Ascendant or Midheaven lines.
- On a sidereal chart the crossings are still correct, because the natal lines and the transit curves shift together.
That list is the reason to trust the crossings it does draw. The midpoint calculator is the free equivalent for the dial arithmetic underneath it.
How this table was built
Positions come from Swiss Ephemeris-grade calculations through Astrolium's astronomy engine, resolved to the ecliptic at 0h UTC each day. The baseline is 0° latitude, 0° longitude — the standard for reference ephemerides. For personal transits tied to your birth chart, use the Transit Report Calculator.
Related tools
- Transit Report — how current sky positions aspect your natal chart
- Profections Calculator — annual timing technique showing which house is activated each year
- Planetary Hours — refine timing within a day by planetary hour
- Void-of-Course Moon — Moon periods when no major aspects complete before the next sign ingress
- Midpoint calculator — the 90° dial arithmetic the graphic ephemeris draws
- Transits — the in-app time navigator with activation windows and per-body orbs