Planetary Pictures: Midpoint Equations in Uranian Astrology

A/B = C says that the midpoint of A and B falls on C. In plain language: the blended theme of A and B is being expressed through C. If Sun/Mars = MC, the blend of identity (Sun) and drive (Mars) is focused on career and public standing (MC).

The equation works in all directions. A/B = C also means A/C = B and B/C = A. All three pairings share the same structural relationship. Uranian astrologers check all three readings to get the full picture.

Each planet has core themes. Sun = identity, Moon = emotional needs, Mercury = communication, Venus = values and attraction, Mars = drive and conflict, Jupiter = growth and excess, Saturn = structure and limitation. The midpoint blends two of these, and the third factor shows where or how the blend manifests.

Venus/Saturn = Moon, for example, might describe emotional experiences (Moon) colored by the tension between desire (Venus) and restriction (Saturn). In practice, this often shows up as loyalty, loneliness in partnerships, or emotional caution.

Alfred Witte developed the planetary picture system in Hamburg in the 1920s. His students Friedrich Sieggrun and Hermann Lefeldt, with publisher Ludwig Rudolph, helped systematize the interpretations. Lefeldt is the author who codified the work into the Regelwerk fur Planetenbilder (Rules for Planetary Pictures), first published in 1928 and still the standard reference today.

The Regelwerk contains a keyword delineation for every possible three-factor combination. The entries are short, almost telegraphic: "Joint enterprises. Working together with others. Community work." The brevity is intentional. The reader adapts the keywords to context.

Reinhold Ebertin's Combination of Stellar Influences (COSI), first published in 1960, is the practical reading companion most modern astrologers use alongside the Regelwerk. Ebertin streamlined the system by removing the hypothetical Trans-Neptunian Points and focusing on the visible planets plus angles. His delineations are more accessible than the Regelwerk's terse style and are the entries most midpoint sorts and software interpretations are derived from.

Suppose your Mars sits at 4° Aquarius and your Saturn at 22° Aquarius. The Mars/Saturn midpoint falls at 13° Aquarius. If natal Sun sits within 1.5° of that point (say, 14° Aquarius), the equation Mars/Saturn = Sun forms with a 1° orb.

Ebertin's classic delineation in COSI for Mars/Saturn = Sun is short and famous: "the hard worker." The blended theme is effort meeting resistance (Mars + Saturn) expressed through identity (Sun). The person tends to define themselves through disciplined, sustained labor and to identify with the experience of pushing against obstacles. The shadow side, Ebertin notes, is exhaustion and danger to vitality if the work is taken too far.

Notice how the reading combines the factor themes (drive, structure, identity) and weights them by the configuration's orb. A 1° orb is firmly within the 1 to 1.5 degree standard, so the picture is active. A 0.2° orb would be unmistakable; a 1.4° orb would still register but more softly. The keyword chips on each scanner result are the starting vocabulary, not the conclusion. Combine the themes, weight by orb, and read in the context of the full chart.

A full midpoint table for a chart can produce dozens of planetary pictures. Not all of them are equally important. The standard approach is to prioritize pictures that involve personal points: the Ascendant, Midheaven, Sun, Moon, and Lunar Node. The five most personal axes are formalized as the Basic Five.

Orb matters too. A picture with a 0.1-degree orb is much more reliable than one at 1.4 degrees. When you are starting out, focus on the tightest structures first. If the chart has a planetary picture at 0.2 degrees, that one is likely describing something the person recognizes immediately.

Witte and Sieggrun introduced eight hypothetical points beyond Pluto, called the Trans-Neptunian Points (TNPs) or Hamburg School transneptunians. They are not physical bodies that have been observed. They are calculated points that Witte derived empirically from chart work and that have remained in use for nearly a century in the Hamburg School tradition.

The eight TNPs and their core themes are: Cupido (community, family, art), Hades (decay, depth, the buried), Zeus (creative force, leadership, controlled aggression), Kronos (authority, mastery, the apex), Apollon (expansion, multiplicity, science and trade), Admetos (concentration, depth, beginnings and endings), Vulcanus (raw power, force, the inevitable), and Poseidon (spirit, ideation, the immaterial).

Ebertin and the cosmobiology school dropped the TNPs in favor of working only with visible bodies plus angles. Strict Hamburg School practitioners keep them. The choice is up to you: add them when you want to extend a reading into themes the visible-planet vocabulary cannot reach, leave them off when you want a more conservative analysis.