Medium Coeli (MC) is also called the Midpoint, because it is the Zenit of the Zodiac in the horoscope. Its counterpart is Imum Coeli (IC) the lowest point on the3 Zodiac, below the horizon.
     Medium Coeli is not a heavenly body at all, but treated much the same in astrology. It moves much faster than any of the planets: the full circle of the Zodiac in 24 hours, just like the Ascendant. Therefore it is necessary to know the exact time of birth, in order to establish the correct MC.
     Because the Ascendant is the eat horizon, and MC is Midheaven, the normal distance between them is 90°. But it can differ, because of celestial and heavenly angles. Still, MC is never below the horizon, and positions close to 90° from the Ascendant are the most common ones in horoscopes.
     In the horoscope, Medium Coeli represents one's image of oneself, how you perceive your own personality. That might be close to how you really are, but that's not at all necessarily so. We all risk fostering completely delusional images of ourselves - to some extent it's what we like to do: regard ourselves as fancier than others are likely to describe us.
     We also tend to present ourselves to others (through the Acendant) in a way that we ourselves regard as far from the truth. That's shown by the normal right angle between the two points of the horoscope. It is typical for the human character not to trust that what we believe ourselves to really be is enough to impress others. So, we play roles.
     Anyway, what we believe ourselves to really be is exactly what Medium Coeli presents in the horoscope.

Aspects to MC
The aspects (special angles) that the MC has to planets in the horoscope show to what extent we agree or are aware at all of other sides of our personality.
     So, an opposition to a planet shows that we refuse to recognize or accept that side of our character, whereas a conjunction means that we are completely convinced about the existence and importance of that side to us. A trine or sextile means a positive attitude to the character in question, but a square means struggle with it. If there is no aspect at all between the MC and a planet, it means that you're not aware of this side of yourself at all.

House
In some House systems, MC is always the cusp (starting point) of the 10th House. But in other systems, such as Equal House, it can be in anyone of the 7th to 12th House. The deviation from the cusp of the 10th House depends very much on the latitude of the place on which the horoscope is based - the farther from the equator, the farther from that point MC can be. Most common, though, is a position in the 9th or 10th House.

Keywords
Here are the twelve Zodiac signs, and keywords for the character they give to Medium Coeli, i.e. the image you have of yourself:
    Aries   winner
    Taurus   steady
    Gemini   charming
    Cancer   caring
    Leo   proud
    Virgo   diligent
    Libra   ethical
    Scorpio   intriguing
    Sagittarius   independent
    Capricorn   competent
    Aquarius   profound
    Pisces   weak


© Stefan Stenudd, 2008