Aspect

Every planet has a position along the ecliptic, given in degrees from 0 to 360. Subtract one from the other and you have the angle between them. The major aspects are the angles you get by dividing the full circle by small whole numbers. Split 360 in two and you get the opposition at 180 degrees; in three, the trine at 120; in four, the square at 90; in six, the sextile at 60. Zero degrees apart is a conjunction. Divide by larger numbers and you reach the minor aspects, like the 45-degree semi-square (one eighth of the circle); the 150-degree quincunx is five twelfths.

Tradition sorts the aspects into families. Squares and oppositions are the hard aspects, read as tension that demands action. Trines and sextiles are the soft aspects, read as ease and support. The conjunction merges two planets and takes its tone from them. A reading looks at which planets are in aspect and how tight the angle is, because a closer aspect is felt more plainly than a loose one. The planets involved matter as much as the angle, since the same square reads one way between the Moon and Venus and quite another between Mars and Saturn.

Suppose the Sun sits at 10 degrees of Aries and the Moon at 12 degrees of Cancer. The gap between them is 92 degrees, close enough to the 90 of a square to count. An astrologer would read that as inner friction between what you want and what you feel, the kind of pull that keeps a person restless until they work it out.

An aspect is the angle, not the sign: two planets in the same sign are not automatically conjunct, and two planets in neighboring signs can be. Beginners often count aspects by sign alone, which is a rougher whole-sign method, when most modern readers measure the exact degrees and apply an orb. Major and minor aspects are weighed differently, and the minors are given tighter tolerances.

The NovaOracles compatibility tool maps the aspects between two people's planets, and the transits guide shows how the sky's current aspects touch your chart.