It will be important for you to get some idea as to what your own natal horizon looks like. At the present time this is made difficult due to the fact that tedious trigonometric calculation is the only way to plot the horizon on a star map. There are computer generated star map programs available. Here is what you will need:

• Plot your RAMC line on a star map (also the line 180° opposite).

• Mark in your Zenith on the RAMC line at the declination that equals your geographic latitude at birth.

• Count South from the zenith (for the northern hemisphere) 90° to find your South Point.

• Plot your Nadir and count north 90° to find your North point.

• The intersection of your horizon line to the line of the celestial equator will be two points 90° (+/-) on either side of your RAMC.

• Perhaps you already have such points along the ecliptic as the ascendant and descendant. These will give you two more points. Now, sketch a line through the points you have found that represents a smooth curve such as the line in our diagram. You will have some idea as to what the natal horizon looks like and how the horizon sphere was oriented at your birth to the rest of the cosmos.

There are yet other coordinate systems of interest to astrology besides the ecliptic, equator and horizon systems. There is the equator of the Sun and the Invariable Plane of the solar system (described elsewhere) as well as the orbital and equatorial planes for the various planets. Beyond our solar system are much larger orderings of stellar material such as the local system of stars in the solar neighborhood, the galaxy to which we belong, the local group of galaxies that includes our galaxy, and the local supergalaxy or cloud of clusters of galaxies.