Visual Astrology
by Michael Erlewine

Much of this will be clear through study on your part. I have found that it is very difficult to explain these different coordinate systems in words. Illustrations help a lot and drawing out your own horizon helps most of all. I apologize for the awkwardness of this presentation and can imagine an entire book devoted to a careful presentation of these three coordinate systems.

Let us review these systems once again. We will examine some diagrams that represent the systems at work in a natal chart. Be sure you understand each of the following statements:

• The birth day is July 18, and the Earth is at 295° or 25° Capricorn along the plane of the ecliptic.
• The Sun in this natal chart is at 25° Cancer or 115° of Absolute Longitude.

• It is Summer in the northern hemisphere since the arctic circle is exposed to the Sun.
• Half the Earth is in darkness, half in light.
• Noon is that point on the Earth that is in line with the Earth/Sun axis in Figure A.
• The time of birth is in the later afternoon.

Figure B represents the Earth and/or the celestial sphere. The zodiac or ecliptic is surrounding the Earth, and the North Pole tilted toward the solstice point. Then:

• A late afternoon birth puts the birthplace to the right of the Earth/Sun line and toward the twilight region of the globe.
• The birth geographic latitude is 40°.
• A line from the North Geographic Pole (or celestial pole) through the birthplace and on to the South Pole represents the RAMC for this birth.
• The point where it cuts or intersects the zodiac is the M.C. (25° Virgo).

• The Zenith (Z) extends out above the birthplace (dark dot).
• The plane of the horizon is 90° from the zenith.
• The intersection of the horizon to the zodiac at 7° of Sagittarius and Gemini marks the ascendant and descendant axis.
• The horizon system is oriented or tilted toward 7° Virgo. This point is called the Nonagesimal, a point on the ecliptic +/- 90° from the ascendant/descendant axis and near the zenith.
• The Prime Vertical intersects the ecliptic to form the vertex and anti-vertex.

© Copyright © 1997 Michael Erlewine