Astrology Systems

Astrology Systems

There are many different systems of astrology that have developed over the years in any different parts of the world. This essay is an attempt to describe many of them and to help understand how they are being used.

Annual Path of the Earth System

Sun system: This system is based upon the yearly movement of the Earth around the Sun. This movement creates four main points: The Spring Equinox, which is the beginning of Spring where day and night are of equal length; the Summer Solstice, which is the beginning of Summer where the day is longest; the Fall Equinox, which is the beginning of Fall where day and night are equal; and the Winter Solstice, which is the beginning of Winter where the day is shortest. Over the course of time, the Greeks realized that each season could be divided into thirds, thus, creating 12 separate stages of the Earth’s annual cycle. This is now called the Tropical Zodiac. In this system, the positions of all planets are interpreted with reference to these spaces of the zodiac.

Path of the Moon Systems

Moon system: This system of astrology measures the distance the Moon moves, with reference to the stars, each day. It was noticed that the Moon moves approximately 13 1/3 degrees per day, giving 27 or 28 signs (Nakshatras). It must have taken hundreds of years for the Indians to figure out what characteristics are given to people born when the Moon was in particular positions. This is the origin of the Sidereal zodiac.

Lunation cycle: This system maps the movement of the Moon in reference to both the Earth and the Sun. When the Moon is closest to the Sun (between the Earth and Sun) we do not see the Moon since the Sun’s light is shining on the side opposite our view. We call this a New Moon. As the Moon progressively moves around the Earth we see more of its surface. When the Moon is furthest from the Sun (the Earth is between the Sun and Moon) the entire face of the Moon is lighted. We call this a Full Moon and is considered the strongest phase of the cycle, which takes about 27.2 days.

Ecliptic Path: This system also maps the movement of the Moon in reference to the Earth and Sun. In addition, the path of the Earth around the Sun (the Ecliptic) is also considered. When the Moon is between the Earth and Sun (New Moon) AND is intersecting the Earth’s path around the Sun, the Moon blocks our vision of the Sun. This is called a solar eclipse. When the Moon is furthest from the Sun (Full Moon) AND is intersecting the Ecliptic, the Earth blocks the Sun’s light from the Moon. This is called a lunar eclipse. The points in space where we see a solar and lunar eclipses are called the Moon’s North and South Nodes. These points are opposite each other and move in a counter-clockwise position. The cycle around the zodiac takes approximately 18 years to complete.

Presently, Lunar phases and eclipses are interpreted in the Tropical zodiac. Perhaps, Nakshatras should also be considered since they are the original signs designed to describe the Moon’s path. It may also be the case that neither sign system is applicable since the zodiacs are independent from the lunar phase/eclipse systems.

Rotation of the Earth Systems

Sun system: This system recognizes four important points in space based on the positions the sun takes throughout the day. The Ascendant is the Eastern horizon where the Sun rises each day. Opposite is the Descendant which is the Western Horizon where the Sun sets. The Midheaven is the highest point in the sky the Sun attains, around noon. Opposite is the Imum Coeli which is the lowest point beneath the sky the Sun travels, around midnight. Planets on the Ascendant and Midheaven are considered to have the most personal influence, while planets on the Descendant and Imum Coeli are considered to influence the types of people we encounter in relationships and the home.

House systems: These systems take the four points from the sun’s path in our sky as its origin and makes each point the beginning of its own quadrant. It then subdivides each quadrant by three, thus, creating twelve segments of equal or unequal size (depending on the method). The planetary positions are then analyzed based on which of the 12 sections they occupy. These systems are NOT based upon visual evidence from physical space. They are based upon the assumption that the daily path of the Sun creates a similar division of space as the annual path of the Earth.

Hybrid Systems

Western system: This system takes the 12 signs of the Tropical zodiac as its base then overlays some form of House system onto the zodiac. A variety of techniques such as aspects, harmonics, and midpoints are then applied.

Commentary: The current use of house systems is dubious since they are based on the assumption that the daily and annual movements of the Earth both produce 12 almost identical sections. Yet, the houses are ordered in the opposite direction from the daily path of the Sun.

The annual movement of the Sun starts at Aries then reaches its peak at Cancer. The daily movement of the Sun starts at the Ascendant then reaches its peak at the Midheaven. If the two systems are reflections of one another, then the houses should be have their order reversed. The current 12th house, where planets rise above the Eastern horizon, should be the visible 1st house. The hidden 12th house should be below the horizon where the planets are still unseen.

Vedic system: This system can be divided into two separate systems, which are often used simultaneously. The first utilizes the Nakshatras (27 lunar signs) to interpret the planetary positions and also has a predictive system based upon the Moon’s position within them (Dasa/Bukti system). This is the original Indian astrology system.

The second uses the stars as its reference point for planetary positions just like the Nakshatras. However, it dispenses with the Nakshatras and replaces them with the 12 signs from the Tropical zodiac. The beginning of the zodiac is placed at the beginning of the Nakshatras. (This is called the Sidereal zodiac.) Then a house system, called Whole Signs, is overlayed onto the Sidereal zodiac. This system only utilizes the Ascendant then simply numbers each sign from that point forward in the order of the zodiac.

Commentary: While the pattern of the Nakshatras seems to develop in a similar way as the Zodiac signs, this does NOT conclude that two systems overlap in Sidereal space. This is a large assumption similar to the Western use of house systems.

The Vedic house system, strangely, does not make the assumption that the daily and annual paths of the Sun are mirrors of each other. Instead, it simply uses the Ascendant as its starting point and numbers each entire sign from 1 – 12. The system is very straight forward since it assigns values of good and bad to certain houses and signs in different combinations with each other. The determination of which signs, houses and planetary combinations are good or bad is based upon the experience of past astrologers and is taken by faith with modern Vedic astrologers.

It seems that this system was almost entirely borrowed from Western sources and altered to suite the needs of Indian culture. The emphasis of Harmonic charts, especially the Navamsha (9th Harmonic), is one unique exception.


There are many systems of astrology which work well on their own. However, great care must be taken when attempting to blend systems. Each system must maintain its own rules including the zodiac it originated from. I have drawn two main conclusions from this path of thinking:

First, there are only two options for signs: 1) the 12 solar signs of the Tropical zodiac – which is the day system, and 2) the 27 lunar signs of the stellar sky – which is the night system. Two systems: one solar, one lunar. Neither should be brought into the other. Would it make sense for Western astrologers to interpret the Nakshatras in the Tropical zodiac?

Secondly, it should not be assumed that house systems based upon the daily rotation of the Earth can be interpreted using the zodiac. The spaces created by the Earth’s horizon, Midheaven and Imum Coeli most likely provide valuable information and follow the same pattern as the zodiac. However, this does not mean that the house cusps can be interpreted using the zodiac signs. In every location on Earth other than the Equator, the distribution of signs on the Ascendant (Rising sign) is heavily skewed. Eighty percent of people born in Scandinavia have six Rising signs. It is unlikely that human personality traits could be so unevenly distributed.

Each system developed over thousands of years in its own context. When placed in a different context, a great risk of distortion occurs. We, as astrologers, need to be clear about what techniques we are using, what their origins are, and how they work best. The idea that any blend of any system can be made to work by a given astrologer discredits the fact that Astrology is a science and obeys laws of time and space just as any other natural science. The experience many astrologers have of their system “working for them” does not validate their system, simply that one’s experience tend to follow their beliefs.