Chiron is located between Saturn and Uranus in the Solar System. Originally it was labeled a planetoid, a cosmic object larger than an asteroid, yet smaller than a moon. Also, Chiron is in a different orbit than the asteroid belt, giving rise to the idea that it is something quite different. It was discovered fairly recently, in the 1970s, and has been the object of a great deal of dissension by both astronomers and astrologers.This is due to the fact that after further research, there were indications that Chiron behaved like a comet. It has a very elliptical orbit which can approach the Sun closer than Saturn and further away than the outer edge of Uranus' orbit. It is very bright.
There has been no "official" determination of what horoscope sign it would rule, though the two most popular contenders are Virgo and Sagittarius. Sagittarian defenders feel that it should have that rulership because the symbol for Chiron is a centaur, just as the symbol for Sagittarius is. Virgo promoters feel that the Chironic sympathy towards healing makes it the ideal ruler, and besides, Virgo has to share a planetary ruler with Gemini, and that's not very fair.
The mythological background of Chiron is the centaur blacksmith, a wounded healer and astronomy teacher. Since it's discovery, there have been quite a few remarkable changes in the areas of both healing and astronomy. The changes that come about during the time of the discovery of a new astrological phenomenon and significant transits to it, tell us a great deal about how to interpret it. Major developments in bio-engineering have occurred since Chiron's discovery, and just the effort to determine Chiron's astronomical nature has aided in our understanding.
In the personal astrology chart, we see Chiron representing the way that we have a healing influence on others. This is rarely in terms of physical healing, though it can be. More likely, this will represent emotional, mental or spiritual healing. Chiron's energy forms a bridge between Saturn and Uranus in the astrology chart. Frequently it will indicate an area of deep cultural repression, combined with an almost electric need to rebel against that repression. Often, the area of repression is representative of a soul wound of some sort, which we must learn to heal.
There's nothing superficial about this. The pain that Chiron can indicate in the horoscope is deep and one could spend years in psychotherapy dealing with it. However, the lessons that we learn in our efforts to cope with it, can serve to heal others in a number of ways. My experience with this is that we are looking again at the peculiar blending that Chiron typifies. Chiron was a centaur, a blend of human and animal. The healing discoveries that Chiron seems to represent are those of in vitro fertilization, genetic manipulation and cloning. Astronomically, it acts like both an asteroid and a comet. It's position between Saturn and Uranus is remarkably awkward. Saturn represents the cultural "supposed to's" and structures, and Uranus symbolizes the weird and visionary. There's a big conflict here which I like to call "misfit consciousness". Chiron seems to show us some part of the self that we consider to be unacceptable in some way, but also unchangeable.
The healing that seems to be required by Chiron is that of self-acceptance, even in the face of social unacceptability. We must rise above the perceived restrictions and instead, pursue and acknowledge our own truths. I say "perceived restrictions" because the social restrictions that I perceive may not be ones that you experience. This also seems to be part of Chiron's nature, getting past our own conditioned responses to what is socially acceptable and what isn't. In your circle of friends, my inability to drink alcohol could make me quite an oddball or object of ridicule. In my circle of friends, your need for at least one alcoholic beverage per day could cause people to have serious doubts about you. We may each take our conditioned responses to what is "normal" behavior and what isn't, as a natural reaction, not understanding that both responses are actually conditioned ones.
Sometimes just our effort to heal our chironic wounds, can be healing to others. My having the opportunity to observe you coming out of your Chironic shell, can give me the courage to push through mine some more. With each bit of progress that I make in breaking through my chiron wound, I'm better able to assist someone else with theirs. Just trying to get by on planet earth seems to teach us quite a bit about our wounding. Particularly as we mature, we can find very creative ways to deal with this pain, to heal it and to move forward. The life experience that we accumulate provides its own anesthesia and we can be far less sensitive than we were in our youth.
So far, I've seen a whole lot of discussion and dissension about Chiron and very little in the way of solid, authoritarian statements. Most other astrologers that I've spoken with on the subject seem to feel as I do, that it will just take working with a large number of horoscope charts in order to clarify our interpretations. What I've given above is in large part the fruit of my own experience in working with Chiron professionally. You'll find other ideas in checking with other astrologers. Perhaps this also is part of Chiron's nature. It is very individualistic and unique.