Elongation Chart
Elongation and Visibility
Elongation is the angular distance between a planet and the Sun as seen from Earth. It is the primary factor determining whether a planet is visible to the naked eye. When a planet's elongation is small, it is lost in the Sun's glare; as elongation increases, the planet emerges into visibility.
Key Visibility Thresholds
- Sub radiis (under sunbeams): When a planet is within 15 degrees of the Sun, it enters the zone of solar dominance. Visibility drops significantly.
- Combust: Within approximately 8 degrees 30 minutes of the Sun, the planet is considered "burned" -- overwhelmed by solar light. In traditional astrology, a combust planet is weakened.
- Cazimi: Within 17 minutes of arc of the Sun's center, the planet is "in the heart of the Sun" -- a paradoxically powerful position in classical astrology.
- Heliacal rising: The moment a planet first becomes visible above the eastern horizon just before sunrise, after a period of invisibility. This marks a symbolic "rebirth."
- Heliacal setting: The last visibility of a planet above the western horizon just after sunset, before it disappears into the Sun's glare.
Phase and Strength in Classical Astrology
- Sub radiis (<15 degrees): The planet's influence is diminished, hidden from view.
- Combust (<8 degrees 30 minutes): The planet is severely weakened, "burned" by the Sun.
- Cazimi (<17 minutes of arc): The planet is empowered, sitting on the Sun's throne.
- Heliacal rising: Symbolizes rebirth, renewed strength, and a fresh start for the planet's significations.
- Morning star (oriental): The planet rises before the Sun -- proactive, pioneering energy.
- Evening star (occidental): The planet sets after the Sun -- reactive, reflective energy.
Inner and Outer Planets
Inner Planets: Mercury & Venus
Mercury and Venus orbit closer to the Sun than Earth. Their elongation oscillates around the Sun, never exceeding a maximum angular distance (about 28 degrees for Mercury and 47 degrees for Venus). They alternate between inferior conjunction (between Earth and Sun) and superior conjunction (behind the Sun).
These planets are always seen either as a morning star (rising before the Sun in the east) or an evening star (setting after the Sun in the west). They never appear at midnight.
Outer Planets: Mars, Jupiter & Saturn
Mars, Jupiter, and Saturn orbit farther from the Sun than Earth. Their elongation ranges from 0 degrees (conjunction with the Sun) to 180 degrees (opposition).
- Opposition (180 degrees): The planet is at its brightest, closest to Earth, and visible all night long -- rising at sunset and setting at sunrise.
- Retrograde motion occurs near opposition, as Earth "overtakes" the outer planet in its orbit.
- Near conjunction (0 degrees), the outer planet is hidden behind the Sun and invisible.