Step 3: Label the Four Points of the Cross
Find the Horizon. Across the middle of the chart there is a line that represents the horizon. It goes from east to west, with east on the left of your chart. This is counterintuitive because on a regular map the left side shows west. As we see in this example, this line is often not continuous but is interrupted by the aspects.
Find the Ascendant. As the earth rotates or “falls away” from the fixed stars and sky, it appears that the heavens rise up from the east because we don’t notice the rotation of the earth. The resulting apparent movment of the heavens falling away to the east is most notable on a starlit night. The sign of the zodiac that is rising (=ascending) over the eastern horizon at the moment of your birth is your rising sign (=Ascendant or Asc). For now just mark the point where the horizon meets the Zodiac with “Asc.” We will determine the sign of the ascendant in the next step. Then find its opposite point, the Descendant and label it Des.
Find the MC, and IC. At the highest point in the sky (not necessrily the highest point of the chart) we find the Midheaven. This is where the Sun was at the zenith (or in the south) at the moment in time we are mapping. In Latin the word for Midheaven is Medio Coeli, hence the abbreviation MC. Label it now. The opposite point to the MC, the lowest point in the sky is called the Nadir, or the Immum Coeli or IC. Label it now. In most charts, the cross created by connecting these four points is marked by thicker lines.