There is an ongoing disagreement between astrologers which includes those who have chosen to calculate their charts on the fixed zodiac of the constellations and those who calculate them based on the moving zodiac signs. Vedic astrologers use the sidereal (fixed) zodiac. Western astrologers generally use the moving or tropical zodiac which is encircled by the tropic of Cancer and the tropic of Capricorn. This is the point where the Sun appears to turn from north to south and then again from south to north in its annual path along the course of the ecliptic. The star Spica is the starting point for the sidereal zodiac --- a point in space. The Tropical zodiac begins from the vernal equinox --- a point in time. Both camps seem to be able to produce accurate readings using the favored method, proving once again that astrology is in large part an intuitive art.

No one really knows precisely where the sidereal zodiac starts and that is part of the reason for the confusion. The entire solar system moves approximately sixty miles a second heading in the direction of the constellation Hercules. If we were to use the plane of the ecliptic as a horizon, then the direction of the Sun's path through space creates an angle of almost thirty seven degrees with the vertical polar axis of the ecliptic. Therefore the planets depict vast spirals while the center of gravity of the solar system, the Sun, treks along a line which is part of a larger circle which is centered in an unknown position within the galaxy. At the same time, the Milky Way galaxy rotates around a point in space behind the "clouds" in the constellation of Sagittarius.

Why would the same zodiac apply to both the Northern and Southern hemispheres?

It seems to make more sense that in places below the equator, the entire scheme should be reversed. Many feel that it should be feasible to calculate a bigger zodiac resulting from the motion of the solar system as it relates to the Earth's ecliptic, however, this has not been adequately done yet. There seems to be general agreement among astrologers that the tropical and sidereal zodiacs are presently about one sign out of phase. The meaning of the phrases Age of Pisces and Age of Aquarius must be understood in the context that there are two dissimilar zodiacs involved with one of them moving and the other nearly motionless.