Aspect type
The opposition aspect
An opposition puts two bodies at the far ends of the circle, as distant from each other as the zodiac allows while still counting as a contact at all — and a pair is counted as opposed well before it is exact.
The distance is not the difficulty. The distance is what makes the pair legible: two bodies at opposite ends of a chart are both fully in sight, which is not something that can be said of a pair standing closer together.
What the distance is for
A chart is built on two oppositions before a single body is placed in it. The horizon runs from the rising point across to its opposite; the meridian runs from the highest point of the sky down to the lowest. Each of those four is defined as the far end of another, and each is read as one half of a pair. So a planet opposite a planet is not an intrusion on the chart's shape. It is the chart's shape happening again.
Which is why an opposition tends to read as an arrangement rather than as damage. Two bodies at this angle are not obstructing each other's work; they are describing one subject from either end of it, and both ends are habitable. The question a reading puts to it is rarely which end is right. It is which end has been standing empty.
That sets the terms for what progress looks like, too. An opposition is not usually settled by choosing, because the end not chosen goes on existing and goes on being part of the chart. What moves is proportion — how much of each, and when. Slower than a verdict, and the only answer the geometry actually supports.
What changes the reading
A third body at right angles to both ends changes the figure completely. The standoff acquires somewhere to discharge, and what was an argument between two becomes a pattern in which a third party does most of the visible work. Astrologers call that arrangement a T-square and read it as a thing in its own right.
Support is rarely even. The geometry is symmetrical and charts almost never are: whichever end collects more contacts from the rest of the chart does more of the talking, and a reading that treats the two as equal partners keeps being surprised by the one that is not.
Where the two ends land matters as much as which bodies they are. The horizon halves a chart, and an opposition that crosses it keeps one end in the visible half and one underneath — a different account from an opposition held entirely below, where both ends are private and neither is easy to catch at it.