In the Western system of Astrology, planetary influences work through ‘Aspects’. An aspects is the distance which separates one planet from another or with any point or the horoscope.

All planets can aspect all other planets, but, only the well defined angles must be formed. There are only two kinds of aspects, the benefic or the malefic.

As per astrology, an aspect is an angle that the planets form to each other in the horoscope, and also to the ascendant, descendant,  lower mid-heaven, and other points of astrological interest. Aspects are measured by the angular distance in degrees and minutes of ecliptic longitude between two points, as viewed from Earth. According to astrological tradition, they indicate the timing of transitions and developmental changes in the lives of people and affairs relative to the Earth.

As an example, an astrologer creates a horoscope that shows the apparent positions of the celestial bodies at the time of a person's birth chart.

Overture on Aspect of Astrology

In Medieval astrology, there are certain aspects that are considered favorable and some are considered malefic. In Modern astrology,  these factors of malefic and benefic are not much emphasized. Rather, every aspect is considered to produce some positive or negative results. Also, these astrological aspects place more emphasis on psychology and tendencies.

The german schools of Uranian astrology and its derivative, Cosmobiology, have attempted to take a different approach to the aspects. These aspects have been entirely indifferent from the traditional application of aspects on signs and houses. In this process, they have layed stress on  the power and effect of the various types of aspects. The concept of Cosmobiology over the aspect of astrology, including the planetary midpoints as mentioned in the the publication Reinhold Ebertin’s ‘The combination of Stellar Influences’, has gained wide acceptance among astrologers.

As per the The writings of Françoise and Michel Gauquelin, the significance of planetary configurations in the astrological chart suggests that the semi square and sesqui quadrate, which are considered as ‘minor’ aspects should be in fact considered as major aspect.

The major Aspects of  Astrology

• The Conjunction: A Conjunction is an angle of approximately 0-10°. An orb of approximately 10° is generally considered as conjunction, if the Sun or Moon is not involved, it is considered the conjunction to be a separation of only about ±08°. This is the most powerful aspect, intensifying the effects of the involved planets mutually and being an important point in the chart. The essential feature of a conjunction is that each planet brings out a characteristic in accord with its own nature out of the other planet. This may probably be difficult to achieve without the aid of the other planet. This process, however, will also cause each planet involved to lose some of its true characteristics.
• The Trine: A Trine is an angle of 120°. A separation of 120±04° is considered a trine. The trine indicates harmony, and ease of expression, with the two elements reinforcing each other. The trine is a source of artistic and creative talent, which is innate. The trine has been traditionally assumed to be extremely beneficial, providing ease even if undeserved, but it can be a 'line of least resistance' to a person of weak character. Too many trines are said to make a person weak and unable to cope with adversity. The essential meaning of the trine is momentum. It thus indicates situations or conditions which continue as they are without much input of energy and that tend to build upon themselves.
• The Sextile: As per Astrology, a Sextile is an aspect that is made when two planets are 60 degrees apart. A sextile is considered to be highly benefic, being the sixth harmonic (360 / 6 = 60) of the 360 degree. Because the sextile is the sixth harmonic of the circle, it takes on many of the qualities of the planet Venus, therefore bringing many opportunities to the native. It is similar to trine in the sense that it can bring out or accentuate the good characteristics in a suitable subject, although their influence is not as strong as a trine. It is one of the moderately powerful aspects.
• The Opposition: Opposition is an angle of 180° . An orb of between 5° and 10° Oppositions are the second most powerful aspect. It resembles conjunction, but, the difference is that the opposition causes exaggeration as it is not unifying like the conjunction but instead exalted. So the opposition creates a dynamic and exalted energy between the planets involved, but it can be indicative of tension, conflict or confrontation, due to the polarity between the two signs involved if not channeled constructively. If properly channeled, the native may use it as a creative and an energetic power source.
• The Square: A Square is an angle of 90°  i.e 1/4 of the 360° . An orb is of approximately  between 5° and 10° . In this,  it is usually the Superior planet that has an effect on the inferior one. Basically, the square's energy is similar to that of a trine but it is intensified to such an extent that the energy is said to be stressful. For example, Mercury square Saturn indicates practicality and prudence with thoughts and communication, concentrating on practical matters. It is also indicative of caution in planning and other mental tasks.