Opposition

Two planets sit 180 degrees apart, facing each other across the chart. A birth chart is a circle of the sky at the moment you were born, with the Sun, Moon and planets placed around it. Astrologers care about the angles between those bodies, called aspects, and ☍ is the aspect symbol for the widest one: a straight line through the centre of the circle, with one planet at each end.

Opposition is one of the five classical aspects, often called the Ptolemaic aspects after the second-century astronomer Ptolemy: conjunction (0°), sextile (60°), square (90°), trine (120°) and opposition (180°). Ptolemy counted opposition as signs six places apart, say Aries facing Libra. Along with the square it is usually classed as a "hard" aspect, the kind that brings friction rather than ease.

In a reading, ☍ is usually explained as a tug of war or a see-saw: two parts of you pulling in opposite directions that have to learn to share one axis. Moon ☍ Saturn, for instance, is one classic example, often read as feelings versus duty. Modern astrologers often soften this into balance or awareness, since the two planets also "see" each other clearly across the circle. The glyph itself makes a handy reminder: two small circles joined by a bar, two bodies linked yet apart.

What does opposition mean in astronomy?

A planet is opposite the Sun in our sky, so it is up all night. When Mars, Jupiter or Saturn reaches opposition, Earth sits between it and the Sun. The planet rises as the Sun sets, stands highest around midnight, and is also at about its nearest and brightest for the year. That is why sky guides say "Mars at opposition" when they mean: this is the week to look. Only the planets outside Earth's orbit can be at opposition; Mercury and Venus never get that far from the Sun. In observing notes and almanacs ☍ is the shorthand for this event.

What does it mean when someone sends ☍?

Most likely astrology, or sometimes the night sky. The sign has no life of its own in chat. If it arrives with planet signs or a chart screenshot, it names an opposition in someone's chart or in the current sky, often a full moon (Sun ☍ Moon). A bare ☍ after a quarrel may be a playful "we are opposites", but only someone who reads charts would get it. For anyone else it is a mystery glyph, so if you mean "I disagree", use words.