Few things have impressed humanity as much as an eclipse. The Sun darkening in broad daylight or the full Moon turning red are events capable of halting an army, inspiring collective rites and filling ancient chronicles with omens. Even today, though we understand the mechanism perfectly, anyone who witnesses a total eclipse often feels a sense of wonder that is hard to describe.
How eclipses occur
Eclipses are encounters between the Sun, Earth and Moon in perfect alignment.
- A solar eclipse always happens at new moon: the Moon passes between the Earth and the Sun and covers its disc, wholly or partly, for those standing in the band of shadow.
- A lunar eclipse always happens at full moon: the Earth comes between the Sun and the Moon, and its shadow falls on the lunar disc, which often takes on a coppery hue.
Not every new or full moon produces an eclipse, because the Moon's orbit is tilted by about five degrees to the ecliptic. Eclipses occur only when the lunation happens near the lunar nodes, the two points where the Moon's orbit crosses the path of the Sun. The very name "ecliptic" comes from the fact that it is the line along which eclipses take place.
The Saros cycle
Babylonian astronomers discovered that eclipses repeat with remarkable regularity. After about eighteen years and eleven days the Sun, Moon and nodes return to an almost identical configuration, and a similar eclipse recurs. This period is known today as the Saros cycle. Thanks to regularities of this kind, the ancients could predict eclipses with good approximation.
Eclipses in ancient cultures
Mesopotamia
For Babylonian and Assyrian scribes an eclipse was an omen concerning the king and the kingdom. In the Neo-Assyrian period there was even the rite of the "substitute king": when an eclipse was judged threatening to the ruler, a substitute sat on the throne for a time to take the evil omen upon himself.
Greece
According to the historian Herodotus, a solar eclipse interrupted a battle between the Lydians and the Medes, who took the darkness as a sign to make peace. Herodotus also credits Thales of Miletus with having foretold that event.
The dragon that devours the light
In many traditions the eclipse was imagined as a monster swallowing the Sun or Moon. In India they are the two personified nodes, Rahu and Ketu; in China people spoke of a celestial dragon; elsewhere drums and pots were beaten to frighten it away. The link with the lunar nodes, called in Western tradition the "head and tail of the Dragon", comes from here.
Eclipses in astrology
In traditional astrology eclipses mattered above all in mundane astrology, which studies collective destinies. Ptolemy, in the second book of the Tetrabiblos, counts them among the main causes of events affecting whole countries, and assesses their sign, duration and the planets involved.
In the individual chart astrologers look at:
- The sign and degree of the eclipse, which indicate the general symbolic theme.
- The house of the birth chart in which it falls, that is, the area of life involved.
- Contacts with natal planets, especially the luminaries and the angles.
- The type of eclipse: the solar one, tied to the new moon, is associated with beginnings; the lunar one, tied to the full moon, with culminations and endings.
Eclipses come in series, usually in pairs two weeks apart, and recur along the same axis of signs for a period of eighteen months to two years. Many astrologers read these periods as phases of transformation in one area of life rather than as single events.
A calm approach
Fear of eclipses belongs to an age when their cause was unknown. Today we can grasp their symbolic value without fear. In the reading of Studio Esoterico Cornelio the eclipse represents a moment when a familiar light is briefly darkened, revealing something not normally seen: during a total solar eclipse the stars and the solar corona appear.
Electional tradition advised against beginning important undertakings in the days around an eclipse. You can follow this advice as an invitation to pause:
- watch the eclipse when it is visible, with proper eye protection in the case of a solar one;
- spend a few minutes in silence and reflection;
- postpone non-urgent decisions by a few days if you can;
- note down thoughts and intuitions, rereading them at the next eclipse of the same series.
In short
- A solar eclipse happens at new moon, a lunar eclipse at full moon, only near the nodes.
- The Saros cycle of about eighteen years allowed the ancients to predict them.
- Ancient cultures read them as omens for kings and peoples, or as a dragon devouring the light.
- Astrology considers their sign, house and contacts with the birth chart.
- Today they can be lived as moments of pause and of looking at what usually stays hidden.