A Graphic Ephemeris is a graphic presentation of planetary aspects, including planetary retrogrades, as well as New Moons and Full Moons, generally made for a year's duration. They can show just transiting planets or they can show aspects of transiting planets to natal planets (or to other types of planetary placements, like progressions, returns, composites, etc.). Graphic Ephemerides make it very easy to see planetary aspects and planetary cycles at glance. Once understanding how they work, Graphic Ephemerides can become an invaluable tool for the astrologer or for anyone using therapeutic or healing technologies or methodologies.
If we were to take a series of astrology charts of daily transits, spaced one day a part, we would see the daily movement of all of the planets through their respective signs in each successive chart. If we do this for year, we have 365 charts. If we plot the planetary locations for each day of the year on a graph, we would have a year-long Graphic Ephemeris.
To illustrate this process: The graph below has a horizontal axis showing days and a vertical axis showing degrees (showing just several degrees of one sign of the zodiac in this example). If we take a specific planet's location from each sequential chart and place it as a dot under the corresponding day of the graph, a curved line of the planet's movement over time results.
A planet moves downward through the graph as it progresses in degrees through the sign. When the planet enters its retrograde period, the line changes directions and moves upward in the graph. When it completes its retrograde, it changes direction again, moving downward through the graph. The following graph is an example of Jupiter's movement (during its retrograde) over a few month period.
If there are a few planets moving through the same sign, and we plotted them all on the same graph, we would see their lines cross whenever those planets conjoin. For example, in the illustration below, Mars moves rather quickly compared to Jupiter's several-month transit through a sign, so we see the Mars line enter and exist the graph quickly, covering just a about a month long period. In contrast, Pluto's transit through a sign takes several years due to Pluto's slow movement through the ecliptic. Its retrogrades move only a couple of degrees as well, so the path it makes through the graph is a long horizontal curve.
If we create a graph of each sign, 30° each, and overlay all twelve of them, we now see not only the conjunctions occurring in each sign, but also all aspects that are 30° or a multiple of 30° (semi-sextile, sextile, square, trine, opposition, and quincunx) between each planet. Obviously, you need to know which sign each planet is in to know which type of aspect is occurring. The illustration below is of a full 30° Graphic Ephemeris for the first six months of 2104.
Other types of ephemerides can also be made using different divisions of the ecliptic other than 30°, such as 45° or 90°, which reveal different planetary relationships. Heliocentric ephemerides can be made as well.
Notice how easy it is to quickly see significant aspects. In the ephemeris below, the confluence of bold lines occurring in April blatantly grabs our attention. It includes Pluto, Uranus, Jupiter and retrograde Mars. Also note the quick triggers created my Mercury (vertical green line) and Venus (vertical blue line) immediately before the primary event. Notice as well that the event occurs between the mid-April Full Moon Eclipse and the late-April Solar Eclipse. A picture shows a lot at glance. This happens to be the grand finale of the Jupiter-Uranus-Pluto T-Square that began in August 2013, now completed by retrograde Mars, forming a Grand Square.
Now seeing when this occurs in the ephemeris, we can also create an astrology chart to see the details, as well as to look for other points of interest (in this case narrowing in on the Moon-Pluto lunar activation of this Grand Square).
You can see an example of a more comprehensive Graphic Ephemeris for the current year on the Annual Graphic Ephemerides web page.
Now understanding the basics of how a Graphic Ephemeris is made and how it works, let us now apply this to a Natal Chart. If we plot the planetary lines of a natal chart onto an ephemeris timeline graph, they will simply be flat horizontal lines because the natal chart is a static chart of some moment in time. As an example, we will use one of the examples above (showing the transiting planets in just one sign). Let's say your Sun, Mercury and Jupiter reside in the sign of Taurus, then the graphic ephemeris would look like this following illustration. Now we can easily see which transiting planets conjoin your natal planets and when.
When we overlay all twelve signs with both the transiting planets and the natal planets, we can then see all of the transiting planets aspecting all of the natal planets (all aspects that are 0°, 30° or a multiple of 30°).
Note: Sidereal transit calculations produce aspect dates based on the actual placement of planets in the heavens at the time you were born. Tropical transit calculations do not because they are based upon the location of planets in the tropical signs, which move at the rate of Earth's precession. Thus, the current location of a sign (and the planets within that sign) has moved in the ecliptic by some amount from the location of the sign at the time of nativity. This can be especially significant for slower moving planets, like Pluto transiting the ASC, for example, which can be off by several weeks using tropical calculations. Thus, tropical-based ephemerides produce relative aspects, and sidereal-based ephemerides produce absolute aspects (where planets actually are with respect to the stars—just something to be aware of.