The Astronomy & Astrology of Combustion

Updated: Jan 3

If you follow or study astrology at all, you will eventually encounter the concept of combustion. Let’s explore what it means for a planet to be combust.


Astronomy

Combustion is a form of syzygy, occurring when a planet is in relative alignment with the Earth and Sun. When this alignment happens, the light of the Sun blocks out the light of that planet. That planet can no longer be seen from Earth, and it is considered combust.


To illustrate, let’s take the example of Venus.


Below we have a two-dimensional, not-to-scale representation of the relative orbits of Venus around the Sun and the Sun around the Earth.


(Remember: because we are primarily interested in events here on Earth, we measure everything relative to ourselves. In order to accurately identify the position of other planets relative to Earth, it is vital that we acknowledge the astronomical realities of the cosmos i.e. the Earth orbits the Sun. However, for our purposes, the Sun is seen to orbit Earth.)


In the image below, Venus is combust at positions 2, 3 and 4, as well as 6, 7 and 8. Do you see the syzygy of these positions, the alignment of Earth, Sun and Venus?



So, what are we looking at? I have marked 8 positions of Venus in its orbit as seen from Earth.

  • Position 1: Venus is clearly visible in the East, early in the morning before sunrise.

  • Position 2: Venus approaches combustion, becoming difficult to see. The process of its disappearance is its “heliacal setting in the East.”

  • Position 3: Venus is combust and not visible, overcome by the light of the Sun.

  • Position 4: Venus approaches visibility once again, appearing just after sunset. The process of its reappearance is its “heliacal rising in the West.”

  • Position 5: Venus is clearly visible in the West, shining bright in the evening sky.

  • Position 6: Venus approaches combustion again, becoming difficult to see. The process of its disappearance on this side is its “heliacal setting in the West.”

  • Position 7: Venus is combust and not visible, overcome by the light of the Sun.