Chiron

Chiron isn't a classical planet but a centaur: a small body orbiting between Saturn and Uranus, and for that reason it symbolically bridges the personal (the closer planets) and the transpersonal (the more distant ones). In astrology it's known as 'the wounded healer': it marks the area of life where a deep wound exists, often an early one, that never quite fully closes.

Far from being just a mark of pain, Chiron's position in the birth chart is often also the place from which a person develops a special sensitivity for supporting and helping others going through similar wounds: healing happens, largely, through connection with others.

Because of its highly elliptical orbit, Chiron spends very uneven amounts of time in each sign (between a year and a half and eight years), unlike the other planets. Its sign and house show what that particular wound is about and in which area of life it shows up most.