You can know every planet placement in your chart and still miss the most important part. Knowing that your sun is in Libra and your Mars is in Cancer tells you something. But the angle between them, the aspect, tells you how those two energies relate to each other inside you. That's often where the real story is.

Aspects are the geometric angles between planetary positions, measured in degrees.

The conjunction (0 degrees)

Two planets in the same degree of the same sign. Their energies merge and blend. The result is intensity and concentration. Whether that's harmonious or difficult depends on the planets involved. Venus conjunct Jupiter tends toward expansion and ease. Mars conjunct Saturn creates friction between drive and restraint that requires conscious navigation.

The sextile (60 degrees)

A mildly beneficial aspect. Easy flow between the two planets, an opportunity that's available but requires some effort to activate. Sometimes described as a door that's open but you still have to walk through it.

The square (90 degrees)

Between planets in signs of the same modality but three signs apart. The energies pull in different directions and create tension.

Squares aren't inherently bad. They're the aspects most associated with motivation, drive, and the necessity to do something. Without some tension in a chart, there's often little impetus to move. The challenge is finding a way to honor both planets rather than letting one dominate.

A sun square Saturn creates ongoing tension between self-expression and discipline. The person may oscillate between repressing themselves and asserting in ways that create conflict. But they often develop an extraordinary capacity for disciplined work from that very tension.

The trine (120 degrees)

Between planets in signs of the same element. Natural flow, ease, and support. No effort required.

Trines are pleasant but can become blind spots. Because the energy flows so easily, there's less motivation to develop it consciously. Some people with many trines find their natural gifts go underdeveloped simply because they never had to work for them.

The opposition (180 degrees)

Between planets in opposite signs. Tension that tends to play out externally rather than internally. Often shows up in relationships, where one person embodies one pole and the other person embodies the opposite.

A Venus-Pluto opposition, for instance, might attract relationships that involve power dynamics, because the person is projecting one side of that polarity outward rather than integrating it internally.

Orbs

Aspects don't need to be exact. The allowed range of deviation is called the orb. Most astrologers use orbs of 8 to 10 degrees for major aspects between personal planets, and tighter orbs for outer planets and minor aspects.

The tighter the aspect, the stronger its influence.