Planet Phases

Earth-centered paths subtract Earth’s position from each planet’s position at the same instant. Orbital weave joins their two Sun-centered positions at equal time intervals. Both are geometric projections onto the ecliptic plane at the drawing’s start. The full pattern is shown faintly; the timeline traces the elapsed part and moves the planet markers. Venus’s familiar five petals nearly repeat over eight Earth years; these are astronomical paths, not exact closed geometric figures.

In the combined Earth-centered view, each path has its own distance scale so that its shape remains visible. The weave uses a shared distance scale: distant planets can make the inner orbits look small. Zoom enlarges the center of the drawing; Fit restores the complete frame. Drawings use finite samples, so very long spans can soften the smallest loops. The zodiac wheel uses apparent tropical geocentric longitudes at the selected instant, with its Ascendant on the left. Houses change with both time and location. Whole Sign and Placidus are explicit choices; unavailable Placidus houses are never replaced silently.

Illumination is the fraction of a planet’s disc lit by the Sun as seen from Earth; phase angle is measured at the planet between the Sun and Earth. The outer planets remain gibbous or nearly full. Physical illumination, astrological faces, and the time traced through an orbital drawing are separate quantities. A face (decan) is a 10° division of a zodiac sign. Face rulers follow Lilly–Zadkiel, Chapter XVIII; house topics follow Chapter IV, in Zadkiel’s revised 1852 edition. Sign rulers use the classical seven-planet scheme. Uranus, Neptune, and the dwarf planet Pluto receive placements here, but are not assigned classical rulerships.

For the first face of Pisces, this tool uses Saturn, as listed in Lilly?s original Christian Astrology (1647), p. 66. The local transcription of the revised 1852 table lists Jupiter in that cell. The archive text is preserved as transcribed; the calculation follows the regular sequence.

Positions, illumination, and cycle events use Astronomy Engine 2.1.19 (MIT license). Conjunctions and oppositions use the engine’s relative heliocentric longitude search; maximum elongations use its Mercury/Venus search. Aspects use the existing chart orbs: conjunction/opposition 8°, square/trine 6°, sextile 4°. All calculations run locally. Historical and future dates are accepted within the browser’s finite date representation; numerical failures are reported, and distant dates do not imply modern-era precision. Input calendar and UTC offset are explicit; timeline and event labels use Gregorian dates.

City names, coordinates and time zones come from the local GeoNames catalogue, under CC BY 4.0. A modern city time zone alone does not establish the clock convention used in a historical record.