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Solar eclipse of 1999.[1]

An eclipse occurs either when the moon stands between the earth and the sun and its shadow temporarily obscures the sun (Solar Eclipse), or when the earth stands between the sun and the moon and its shadow temporarily darkens the moon (Lunar Eclipse).


A solar eclipse does occur during a new moon; i.e. when the sun and the moon form a conjunction. This conjunction happens once a month but a solar eclipse only occurs twice a year. When there is no eclipse the moon is located either directly above or below the sun. During an eclipse, the moon's ecliptic latitude needs to be as small as possible. In a natal chart, this is graphically portrayed by the conjunction being close to the moon's nodal axis (Moon's Nodes). Although this usually happens twice a year, rarely it will happen as often as four or five times annually.

There are several kinds of solar eclipse:

Diagram 1: Solar Eclipse
  • A total eclipse occurs when the moon's disk completely covers the sun's, as seen by those at locations within the Moon's umbra (Diagram 1.) For a total eclipse to occur the conjunction must take place within 11 degrees and 15 minutes of the moon's nodal axis.
  • An annular eclipse is similar to a total eclipse, but because of the greater distance between the earth and moon the latter's shadow does not totally cover the sun so that a ring of sunlight around the moon remains visible during the eclipse.
  • A partial eclipse occurs when the moon is not situated directly between the earth and the sun and its shadow only partly covers the sun's surface. A partial eclipse occurs when the moon is further away from its nodal axis: somewhere between 11 degrees 15 minutes and 18 degrees 31 minutes, depending on the distance between the moon and the earth.

A lunar eclipse can only occur at the time of a full moon, i.e. when they form an opposition. The sun opposite the moon also occurs once a month, and the moon normally appears directly above or below the earth's shadow. Up to three lunar eclipses (at most) are possible in one year, namely when the earth is situated directly between the sun and the moon. That means that the opposition must occur on or close to the moon's nodal axis. In some years there are no lunar eclipses.

There are several kinds of lunar eclipse:

Diagram 2
  • At a total lunar eclipse, the earth's shadow completely covers the moon (Diagram 2.) In this case, the distance between the sun-moon opposition and the moon's nodal axis must lie between 3 degrees 34 minutes and 6 degrees, depending on whether the moon is at perigee or apogee.
  • At a partial lunar eclipse, the moon is only partly covered by the earth's shadow. In this case, the distance between the sun-moon opposition and the moon's nodal axis lies between 3 degrees 34 minutes and 12 degrees 15 minutes, depending on whether the moon is at perigee or apogee.
  • A penumbral eclipse occurs when the moon passes through the Earth's penumbra. In this case, the moon's surface becomes only slightly faded as less light is reflected but there is no obvious darkening.

An eclipse occurs every 18 Years plus 10-11 days at the same position in the zodiac. This is called the saros period.

Dragon's head and tail.[2]


Until modern times, most people thought that eclipses heralded disastrous times ahead. The names given to the ascending and descending moon's nodes attest to this, namely the Dragon's Head for the former and Dragon's Tail for the latter. In astronomical folklore an eclipse occurred because a dragon swallowed the moon's light. An eclipse conjunct a natal planet in traditional astrology was a malefic influence. Perhaps as a result, few modern astrologers pay much attention to the eclipse cycle.

Modern astrologers see eclipses are powerful triggers that can activate other horoscope factors, whether in an individual's chart or that of a country.

Not every eclipse has an equally powerful effect. The nearer to the moon's nodal axis an eclipse occurs, the more powerful it is likely to be. In other words, a total eclipse is more powerful than a partial one. Solar eclipses are thought to have a stronger effect than lunar ones.

In order to trigger something in a natal chart the degree at which the eclipse - whether solar or lunar - should ideally be in conjunction or form one of the other main aspects to a horoscope factor in the natal chart. Like a planet in transit (which in effect it is) an eclipse will activate any factor to which it forms an aspect. A total solar eclipse, and to a lesser extent a total lunar eclipse, usually has a powerful effect. I.e., a breakthrough could occur, or an ongoing process might finally be brought to a conclusion. Eclipses are considered to be particularly important in horary astrology. The method known as Astro*Carto*Graphy can help to calculate the locations at which the eclipse is conjunct one of the main axes. To go into more detail it is necessary to check whether the eclipse makes aspects to the sun, ascendant or midheaven of a city, country or head of state.

The effects of an eclipse are felt until the next eclipse of a similar kind, usually in around six months. A solar eclipse can sometimes be felt three to four months before it actually occurs.



  • Burk, Kevin 2011. Astrology: A Comprehensive Guide to Classical Interpretation, Llewellyn Publications.
  • Teal, Celeste 2006. Eclipses: Predicting World Events and Personal Transformation, Llewellyn Publications.


  1. On Aug, 11th.
    Watched out of MIR space station.
  2. Medieval illustration, coloured.