Conjunction 1
A conjunction is when at least two planetary bodies are 0° degrees apart.  Some astrologers say that conjunctions are bad; some say that conjunctions are good.  Both astrological schools of thought agree that a conjunction lends power that is colored by the two dynamic forces that have been conjoined.  It blends the two or more planetary energies.  People with conjunctions are powerhouses.  This aspect resonates with the number one.

Opposition 2
An opposition is when at least two planetary bodies are 180° degrees apart.  An opposition represents half of a 360° circle.  Oppositions are bad aspects that cause strife stemming from an outside source.  Unlike people with squares who cause their own turmoil, the oppositional turmoil will be created by others.  People with oppositions are always experiencing hardships through no fault of their own.  The opposition is a powerful roadblock. This aspect resonates with the number two.

Trine 3
A trine is when at least two planetary bodies are 120° degrees apart.  A trine represents one third of a 360° circle.  The trine is thought to be the most auspicious aspect in astrology, lending a helping hand.  Trines produce easy flowing energy.  People with many natal trines act lazy and spoiled, as everything gets handed to them; they accomplish much with minimal effort.  These people possess less character because they want for nothing. This aspect resonates with the number three.

Square 4
A square is when at least two planetary bodies are 90° degrees apart.  A square represents one quarter of a 360° circle.  Astrologers agree that squares are negative, disagreeable aspects of strife.  Nothing comes easily to people with many squares; they must work twice as hard to achieve half as much.  However, they are strong-willed individuals who can accomplish great things, as they have great stamina.  This aspect reveals internal conflict within the self.  It is a dynamic tension-filled aspect that represents a challenge that meets resistance. This aspect resonates with the number four.

Sextile 6
A sextile is when at least two planetary bodies are 60° degrees apart.  A sextile represents one sixth of a 360° circle.  This beneficial aspect lends opportunity.  It acts to a lesser degree like a trine; however, unlike a trine, it does not give without effort.  Those possessing a sextile will be offered an opportunity, but they must reach for it.  The sextile creates a easy flow of energy.  It reveals where resources can be found. This aspect resonates with the number six.

Quincunx 12

A quincunx is when at least two planetary bodies are 150° degrees apart.  This inharmonious aspect is also referred to as the inconjunct or disconjunct.  Many astrologers consider this aspect to be minor; however, it is not a minor aspect, and the impact can be greatly felt.

With a quincunx, the two signs where the planets lie have absolutely no affinity to one another.  Therefore, it basically represents an inharmonious, unpleasant blend of jerky stop and start energy that cannot seem to merge.  With this aspect, sometimes things flow well; sometimes things don't.  Unlike the conjunction, when two planets join forces, working together, the quincunx is just the opposite.  The two planetary bodies involved in the quincunx will forever waver back-and-forth and can never blend or work together.  If utilizing energy from one planet involved in the inconjunct, the energy from the other planet will remain inaccessible at that moment and vice versa.  

This aspect requires adjustments or compromise. 

In synastry, it is guaranteed that two people having a quincunx involving the luminaries will never stay together because they have nothing in common.  In synastry, this aspect found amongst personal planets represents nothingness, which proves worse than sharing a bad aspect.  This aspect resonates with the number 12. 

Semi-Square 8

A semi-square or octile is when at least two planetary bodies are 45° degrees apart.  A semi-square represents one eighth of a 360° circle.  This minor adverse aspect acts to a lesser degree like a square.  It pinpoints a challenge requiring action that meets resistance.  It is simply felt as an annoyance or restlessness. This aspect resonates with the number eight.

Semi-Sextile 12

A semi-sextile or dodecile is when at least two planetary bodies are 30° degrees apart.  A semi-sextile represents one twelfth of a 360° circle.  Astrologers disagree as to whether to consider the semi-sextile as beneficial or inharmonious.  This inharmonious minor aspect acts much like a lesser version of a quincunx, as the signs where semi-sextile planets lie share no natural affinity with one another much like a quincunx.  This aspect is simply felt as an restlessness requiring readjustment and compromise.  However, it can be helpful, revealing to a lesser extent than the sextile where opportunities and resources lie.  This aspect resonates with the number 12.

Sesqui-quadrate 8
A sesqui-quadrate is when at least two planetary bodies are 135° degrees apart.  This minor adverse aspect is also referred to as a sesqui-square or trioctile, and it acts to a lesser degree like a square.  It pinpoints a challenge requiring action that meets resistance.  It is simply felt as an annoyance or restlessness. This aspect resonates with the number eight.  

Quintile 5

A quintile is when at least two planetary bodies are 72° degrees apart.  A quintile represents one fifth of a 360° circle.  This beneficial minor aspect reveals where an individual naturally possesses tremendous talent.  A quintile acts to a lesser degree like a trine, in that it bestows a free-flowing energy that requires little to no effort.  Quintilian attributes are Mercurial and Virgo-like as this aspect concerns itself with specialization, technique and methodology used to accomplish its creative goal.  The quintile also reveals personal style imparted within the creative efforts.  The quintile series includes the biquintile, decile, tridecile and vigintile.  All related aspects act like the quintile to a lesser degree.  All are considered to be indicators of  where both developed and under-developed unique creative gifts lie.  This aspect resonates with the number five. 

Septile 7

A septile is when at least two planetary bodies are 51.43° degrees apart.  A septile represents one seventh of a 360° circle.  This beneficial minor aspect is considered sacred, and it is believed to be imbued with a deeply spiritual element.  Septiles are not used in traditional astrology, and is mostly used by astrologers whom practice the relatively new astrological delineation methodology called Harmonics.  The septile series includes the biseptile and the triseptile.  This aspect resonates with the blessed number seven.  

Quindecile

A quindecile is when at least two planetary bodies are 165° degrees apart.  This minor neutral aspect is also referred to as a Johndro.  It largely indicates an obsession and/or compulsion quality.  Quindeciles suggest a marked determination or motivation that can be rather disruptive.

Novile 9

A novile or nonile is when at least two planetary bodies are 40° degrees apart.  A novile represents one ninth of a 360° circle.  This minor aspect is helpful.  It is the aspect of completion.  Noviles are not used in traditional astrology, and is mostly used by astrologers whom practice the relatively new astrological delineation methodology called Harmonics.  The novile series includes the binonile and the quadranonile.This aspect resonates with the number nine. 

Decile 10
A decile is when at least two planetary bodies are 36° degrees apart.  A decile represents one tenth of a 360° circle.  This minor slightly beneficial aspect reveals where unique untapped talents lie.  This talent is not nearly as honed as with the quintile, but the decile bestows a gift waiting to be discovered and utilized.  The decile series includes the tridecile. This aspect resonates with the numbers five and/or ten. 

Undecile 11

An undecile is when at least two planetary bodies are 32°44' degrees apart.  An undecile represents one eleventh of a 360° circle.  Undeciles are not used in traditional astrology, and is mostly used by astrologers whom practice the relatively new astrological delineation methodology called Harmonics.  The undecile series includes the biundecile, triundecile, quadraundecile and quintundecile.  This aspect resonates with the master number eleven.