“Aspects” is the term for angular relationships between planets or parts of a horoscope chart. They show how the energies of the planets or parts of the chart work together, and they show potentials for actions or events. For example, imagine two objects close to one another. They might join together as a team or rub each other the wrong way causing friction. On the other hand, two objects facing each other across a circle might balance each other or complement each other, or they could oppose or repulse each other like opposite poles of magnets.
For a quick check of aspects, their symbols and meanings, see my Astrologer’s Apprentice Cheat Sheet.
The aspects exert influence over a range of degrees centering around the exact angle, or arc, of the aspect. This range of influence is called the “orb.” The closer to exact (or “tighter”) an aspect is, the greater its power. Sometimes more orb is allowed when the Sun or Moon is involved.
Most aspects are created when the circle is divided into parts divisible by whole numbers.
no division = 0° (degrees) [orb 8-10°] called a conjunction
360° by 2 = 180° [orb 8-10°] called an opposition
360° by 3 = 120° [orb 8-10°] called a trine
360° by 4 = 90° [orb 8-10°] called a square
360° by 5 = 72° [orb 1-2°] called a quintile
360° by 6 = 60° [orb 5-6°] called a sextile
360° by 7 = 51°26’ [orb 1-2°] called a septile
360° by 8 = 45° [orb 2°] called a semi-square
360° by 9 = 40° [orb 1-2°] called a novile or nonile
360° by 10 = 36° [orb 1°] called a decile
360° by 12 = 30° [orb 1-2°] called a semisextile
Astrologers don’t have a definite rule about how many degrees of orb to use with the various aspects. It’s partly a matter of personal choice as to how much of a range you consider the influence of an aspect to have. The orbs listed above are suggestions.
Of these types of division, some are more powerful, with more noticeable effects and are thus used more frequently by astrologers. The divisions by 5, 7, 9, 10 and 12 are not as influential as these other divisions and are called minor aspects. Even more minor would be multiple fraction aspects formed from these, like the biquintile (144°), fairly commonly used, and the quite obscure biseptile (102°52’) or aspects with no names, like 3/8 or 5/8. The eighth-multiples, and even multiples of sixteenths, are used primarily only by a certain system of astrology called Uranian astrology, developed in the 20th Century by Germans. (In the 21st Century, this is sometimes now called Symmetrical Astrology.) It is very mathematical and uses very tight orbs for all aspects. It pretty much ignores the 1/3 (trine) and 1/6 (sextile) aspects, which are considered quite important by most other astrologers. Noel Tyl has made quite a study of an aspect he calls the quindecile (165°), which he says indicates obsessions. I can’t speak to that since I haven’t studied it.
There are some additional aspects not formed by dividing the circle by a whole number. For instance, the quincunx (also called inconjunct) is 150°, the distance of five 30° signs apart. This is a little more important and more often used than the minor aspects. There is also the 135° aspect, like a square-and-a-half, with the unwieldy name sesquiquadrate or sesquisquare. When it is considered useful by an astrologer, usually the semisquare (45°) is also used.
Some astrologers consider certain aspects to be easier to handle than others. Generally trines, quintiles, sextiles and semisextiles are considered to bring pleasant effects and conditions (and are referred to as easy aspects) while oppositions, squares, semisquares and sesquiquadrates are considered to bring unpleasant effects and conditions (and are referred to as hard aspects).
Here is how the parts of a chart get along when connected by the aspects [the brackets show the number degrees between the involved chart parts and the orb allowance for the aspect]. The major (most often-used and considered strongest) aspects are CAPITALIZED. These are known as the Ptolemaic aspects, those favored by the prolific ancient Greek astrologer Ptolemy.
CONJUNCTION [0° + or – 8-10°] adds a heavy emphasis, their forces combine and strengthen, adding power in the sign and house areas of the conjunction (whether a conjunction is pleasant or unpleasant depends on the planets or parts of a chart involved and the signs they’re in and how well those blend)
TRINE [120° + or – 8-10°] harmony, ease of expression, can lead to inertia and laziness, automatic benefits with even greater rewards/effects when some effort is applied
SEXTILE [60° + or – 5-6°] opportunities for help, harmony and ease between energies but effort is definitely required for benefit and awareness
Semisextile [30° + or – 1-2°] slight ease, opportunities, resources
OPPOSITION [180° + or – 8-10°] difficulties from outside forces, requires a compromise, shows alternatives, leads to growth through awareness
SQUARE [90° + or – 8-10°] apparently irreconcilable desires which may lead to going around in circles, struggle leading to action, must learn to satisfy both urges or give one up
Semisquare [45° + or – 2°] strain, conflict necessitating action
Sesquiquadrate [135° +or – 2°] challenges, friction leading to action
Quincunx (also called Inconjunct) [150° + 2°] a psychological challenge, unconscious pattern of scattered energies, something left incomplete requiring adjustment or compromise or bridging
Nonile (also called Novile) [40° + 2°] fated things, compulsions, may have to do with creativity or completion
Septile [51°26’ [+ 2°] similar to the nonile but with a spiritual side
Quintile [72° + 2°] unique abilities or talents, easily developed
Biquintile [144° + 2°] like the quintile, perhaps a bit weaker in influence
More than two astrological objects may be involved in an aspect. For instance, two planets may be conjunct and both may be opposite and third. But say these three are square to a fourth. This is then an aspect pattern involving almost half the planets and is a focal point of the chart. There are names for certain patterns. The one described above is called a T-square since a “T” is formed. There is also a Grand Cross with two pairs of oppositions at right angles (square) to one another. An equilateral triangle is called a Grand Trine.
Aspects seem to operate more intensely as they are come to the point of exactness, called “applying,” more than after they have already been exact and are moving apart, called “separating.” For instance, the square aspect is exact at 90°. If two planets are 87° degrees apart, the square is applying. If they are 93° apart, the square is separating. Always look at the faster planet in relation to the slower one. The planets are generally faster the closer they are to the Sun in this order: Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto. (The exception to this general rules occurs when planets appear to come to a halt in the optical illusion called “retrograde” motion.) The Moon is closest to earth and is thus the fastest of the heavenly bodies from our perspective. So if the quick Moon is 118° behind slow-moving Saturn, it is moving out of a 120° trine as it gets closer to Saturn; this is called a separating aspect. If the Moon is 118° ahead of Saturn, it is moving into the trine, called an applying aspect.
Another way of looking at aspects is to see if they occur in the first half of the phase relationship between the planets or in the second half. When a faster moving planet passes a slower moving planet, they are conjunct. When the faster one gets halfway around the circle from the slower one, they are opposite. The period in between the conjunction and the opposition is called the “waxing” part of the phase. The second half, from opposition back to the next conjunction, is called the “waning” part of the phase. You are already familiar with the waxing and waning Moon. From the New Moon (conjunction of the Moon to the Sun) to the Full Moon (opposition of the Moon to the Sun) is the waxing phase, where the Moon appears to grow bigger and bigger. From the Full Moon back to the next New Moon is the waning phase, where the Moon appears to contract in size.
Any pair of planets can be considered in a similar fashion, although neither appears to change in size the way the Moon does in this example. On an interpretation level, we say that the energy exchange between the planets is slightly different in the waxing phase versus the waning phase. There is a more subconscious or instinctual component to the waxing phase and a more conscious or informed component to the waning phase, since the opposition (which divides the phases) is thought to bring awareness or objectivity. Or we might say, the energy is increasing or growing during the waxing phase and decreasing or declining when waning.
Usually when astrologers discuss aspects between planets, they are referring to the spatial relationships as viewed from earth (since that is where we live). These are technically known as geocentric aspects. There is also such a thing as heliocentric positions of the planets and hence heliocentric aspects. This would be as viewed from the true center of our solar system, the Sun. Some astrologers like to look at the heliocentric positions in addition to the geocentric ones. In interpreting the heliocentric positions, it is thought they represent interactions with the larger world or a bigger scope of reference than geocentric, which might be more individual or personal in meaning. (See The Mountain Astrologer, Issue #87, p. 58.)
Speaking of things other than personal and individual, did you know not only humans have horoscope charts? Anything that has a beginning point in time can be charted. Examples would be: a building’s cornerstone or dedication ceremony; an automobile rolling off the assembly line; an animal being born; a business making its first transaction or its stock first being traded; an airplane flight taking off or the beginning of any kind of journey or travel; a wedding (use the time of pronouncing as husband and wife); a fire starting; the list is endless. “Mundane” (meaning “of the world”) astrology studies everyday occurrences, events and non-human entities.
Aspects are considered not only in the “natal” or birth charts (whether human or not) but are also examined as they occur over time. This is part of looking at what is called “transits,” the ever-changing positions of the planets in the heavens as they move through the signs, whether viewed geocentrically or heliocentrically. Transits and their aspects are the “meat” of astrological forecasts. For instance, if there is a potential in the natal chart for difficulty with finances (perhaps a square from Venus, ruling money matters, to Saturn, indicating hardship or a lack), it is most likely to manifest when there is a transiting aspect to this natal pattern, say when the position of Uranus (meaning surprises) becomes opposite to the position of either Venus or Saturn. This would form a temporary “T-square,” and around the time of that moment, give or take a few days (allowing some “orb”), it’s very likely something surprising – and not necessarily pleasant – will occur with financial impact.