When two planets or important points of the astrological chart form an angle, that’s called a planetary aspect or astrological aspect. When looking at the chart, the direction of the angle isn’t important: no matter if (for example) a 60 degree angle is on the right or on the left side of the astrological circle (so clockwise or counterclockwise), the aspect is still a sextile.
When analysing a chart, you shouldn’t look only at exact aspects, so when the angle is of exactly x degrees. The influence of the planets can be felt already days, weeks or even months before they form the exact angle (depending on the size of the planets involved). We are not talking about a square only at an 90 degree angle, but also when the angle is of for example 88 or 92 degrees. The difference between the planet and the exact aspect is called orb. For example: if a planet is 2 degrees away from forming a conjunction (before or after the exact conjunction), we’re talking about a conjunction with an orb of 2 degrees.
Each astrologer can decide for himself/herself which orb to consider, depending on the planets that are involved. When trying to establish the exact moment of an event or when attempting to answer a question using the horary astrology, one will use tighter orbs (1-2-3 degrees). For the analysis of a birth chart, orbs of 5-8 degrees are not uncommon.
The major aspects
The conjunction: Two (or more) planets form a conjunction when they seem to be very close to each other (looking from the Earth), so when the distance between them is of 0 degrees. The planets’ energy is now combined and the planets will influence each other. Conjunctions can have positive or negative influences, depending on the planets/asteroids/points that are involved and also on the sign where the conjunction is happening.
The sextile: An aspect formed when the planets are 60 degrees (so two zodiac signs) apart. The sextile is a positive aspect, showing a certain potential that we could use in order to evolve.
The square: When the distance between the planets is of 90 degrees (three zodiac signs apart), they form a square. The square is a negative aspect and causes tensions, conflicts, problems.
The trine: This is an aspect formed by planets that are 120 degrees (four zodiac signs) apart. The trine is a positive, harmonious aspect. It indicates that the energy between the planets is balanced and it’s usually a source of support.
Opoziţia: Planets that are 180 degrees (six zodiac signs) apart form an opposition. This aspect is usually negative, but it can also be used in a constructive, positive manner. The opposition indicates challenges, but this also means that things are dynamic. Even if the powers involved seem to pull in different directions, one can overcome the tensions or use the conflict to his/her advantage – thus evolving as a person and turning the opposition into a positive aspect.
The semi-sextile or dodecile: When the planets form an angle of 30 degrees, they form a semi-sextile (half a sextile). This means that the planets are located in consecutive signs (for example Aries and Taurus). The semi-sextile can cause small problems, but usually it indicates two powers that complement each other. The planet that is located “ahead” somehow smooths the way for the second planet – which should be regarded as a chance, as an opportunity. The semi-sextile is also called dodecile, from the Latin duodecim, because it’s the 12th part of a circle.
The semi-quintile or decile: An angle of 36 degrees (the 10th part of a circle, thus decile). This is an aspect that astrologers use rarely and with an orb of maximum 2 degrees. It’s meaning is similar to that of the quintile, but its influence is weaker.
The novile: When two planets or important elements of the chart form an angle of 40 degrees, they form a novile. This aspect usually indicates something that ends in order to make place for something new. But its influence is very week, most people don’t even feel it.
The semi-square or octile: Aspect formed by two planets/important points that are 45 degrees apart (so half a square, which would be 90 degrees). The semi-square’s meaning is similar to that of a square, but its influence is weaker. This aspect is also called octile, because it’s the 8th part (Latin: octo) of a circle.
The quintile: If you divide the astrological circle into five (Latin: quinque) equal parts, you the angles will be of 72 degrees. That’s a quintile. This aspect usually indicates a certain talent or potential that can help us become more creative. Its meaning is similar to that of a trine, so the planets will influence each other in a positive manner – but the accent lies on the creativity and on the ideas that help us find a solution to a certain problem.
The sesquisquare or trioctile: Sesquisquare means “a square and a half”, trioctile means “three octiles”. So we have 90 + 45 degrees or 3*45 degrees = 135 degrees. The sesquisquare indicates something irritating, a certain tension. But its influence is weaker than that of a square or of a semi-square and people usually ignore it. The problem (especially when the sesquisquare is a part of the birth chart): by ignoring this aspect, the tension will always be somewhere in the background – and one won’t be able to understand where the problems are coming from.
The biquintile: When two planets or important points are 144 degrees apart (two quintiles, so 2*72), they form a biquintile. Its meaning resembles that of a quintile: the energies of two planets confer us creativity and the ability to solve certain problems.
The inconjunct or quincunx:
Aspect format de două planete sau puncte aflate la o distanţă de 150 de grade. Inconjuncţia indică, în general, o provocare, dar nu se poate spune că efectele sale sunt numai pozitive sau numai negative. Acest aspect este cel mai important dintre cele minore, fiind luat în considerare deseori chiar şi de astrologii care nu interpretează alte aspecte minore
The quindecile: Two planets or important points that are 165 degrees apart. This is a “new” aspect, that wasn’t used in “traditional” astrology – but it became more important during the last century. It indicates a trauma or an element that can lead to a growing obsession. The name of this aspect is actually incorrect and caused quite a controversy: following the “rules” applied to the other aspects, the quindecile should be the 15th part of a circle (Latin: quindecim). That’s 24 degrees, not 165.