What this aspect is
A hundred and eighty degrees, half the circle. The planets stand in opposite signs of the same modality: they speak about the same thing in opposite ways. The orb matches the conjunction: up to 12 degrees for the Sun, 10 for the Moon, 5 between the other bodies.
In the natal chart
An opposition differs from a square in that the conflict is not inner but outer: the other side usually arrives through people and circumstances. The typical scenario is projection, where one's own need looks like somebody else's demand. Working with an opposition means holding both poles rather than defeating one.
In transits
A transiting opposition is the midpoint of a cycle that began with a conjunction: what was set in motion shows its result and meets an outside reaction. For slow planets that point falls in the middle of the 12 or 29 year revolution, which is why the oppositions of Saturn and Jupiter to natal planets are clearly visible in a biography.
Common reading mistakes
The opposition is often read as a conflict with people and left at that. The other end of the axis belongs to the person themselves, it simply shows up through those around them. The second mistake is confusing it with the square: in a square the tension is inner and demands action, in an opposition it lies in choosing between two poles that are both needed.
Major aspects
Orb by body
- Sun 12°
- Moon 10°
- Mercury 5°
- Venus 5°
- Mars 5°
- Jupiter 8°
- Saturn 5°
- Uranus 5°
- Neptune 5°
- Pluto 5°
The orb of a pair is the smaller of the two numbers. A Sun conjunct Pluto counts up to 5 degrees, because that is Pluto's figure, even though the Sun's is 12.