Opposition
How it is defined
The exact angle and the allowed tolerance, called the orb, are different quantities. Set the criterion before interpreting. A separation in longitude does not mean the bodies touch or align in all three dimensions.
How to read it
In astrological language this is associated with polarity and a search for balance. Its nuance depends on the positions and question, without automatically guaranteeing a favourable or unfavourable outcome.
A concrete example
Geometric example: positions at 10° and 190° have a separation of 180°. In a disagreement, distinguish two apparently incompatible needs and look for a concrete way to negotiate between them.
Explore further
When comparing charts, check the orb and system used. This website’s birth chart provides Sun, Moon and ascendant; this entry explains aspects without adding them to that tool’s results.