Why do astrological and astronomical movements not match?
The constellations used to indicate the twelve signs of the Western zodiac were chosen because for a few thousand years they were consistently in their places when the energies of the world and the people entering it shared certain qualities and elements which were then associated with those signs. As recorded history has progressed we’ve realized that, as with all things, the solar system, the galaxy, indeed the Universe itself are constantly changing, and as we find new patterns and cycles in these changes they’re incorporated into the art of astrology. This particular issue of precession is being addressed in sidereal and esoteric astrology which are in turn changing the face of the art as a whole, but because the constellations were only used as markers of certain aspects between the Earth and the Sun the energies themselves remain the same. Thanks to the huge scale of these changes, we have plenty of time to work things out along the way without losing the efficacy of the art.