What we know as "horoscopes" in Western astrology is the Sun sign, meaning the sign that the Sun was in at the moment we were born. Another very important part of astrology is our Moon sign. Our personal birth chart shows we are deeply affected at all levels of our existence by the positions of stars at the time of our birth. The moon has a very strong effect on us because it is a satellite of our planet and is physically closer to us than other planets. We know that the Moon is responsible for creating tides in particular. Science has shown that the Moon affects matter in its liquid form. A great portion of our body is made up of water and so, the Moon has a direct effect on us. The position of the Moon in a person's birth chart is of great importance and it shows the individual's attitude towards life, subconscious reactions and the underlying factors in strong fundamental behaviors. The Moon may be at a stronger point than the Sun in some cases and thus, its effects might be more visible than the sign where the Sun is.
In a birth chart, the Sun sign symbolizes the Self, Consciousness and Spirit while the Moon shows the Supraconscious, memory, our automated reactions and the Mother archetype. The Moon displays its characteristics according to the sign and house it is in and according to its angles to other planets. According to astrology, the Moon also represents the mother quality or womanhood in general. While the Sun creates our identity as seen from outside and our ego, the Moon gives shape to our inner nature and our hidden aspects. It rules our subconscious, thus knowing the effects of the Moon in our birth chart can help us better understand ourselves.
The sign in which the moon and sun are in according to our birth chart and their aspects with other planets affect our physical and spiritual make up. If the Moon rules our birth chart, we have a tendency to use more the left sympathetic nervous system, i.e. our left (feminine) energy channel. If we were born under the strong effect of the Sun, we are probably more inclined to use the qualities of our right sympathetic system, in other words our right (masculine) energy channel, thus demonstrating a more active, rational and stronger personality.
We might be bearing not only the positive but the negative influences of the Moon and Sun as well. For instance, our left energy channel could run out of energy if we over emphasize emotion and the past, which are governed by the Moon. Such a person normally lives in the past, is very emotional, overly sensitive and is prone to psychosomatic diseases. On the other hand, if we use the Sun channel too much, we can become too active, dry, angry, egoistical.
However, the aim of a birth chart and of life is to attain balance by harmonizing the effects of planets within us and with the cosmos. We can attain this balance if we know how to harmoniously use the subconscious and conscious, emotions and mind, masculine and feminine qualities, instinct and the mind which all exist in our left and right channels. This is achieved through the parasympathetic nervous system, which corresponds to the central channel in the yogic traditions. The hidden energy called in yoga as Kundalini, which lies dormant in every human being since birth, can rise through the central channel and connect us to the universal consciousness. This process is called self realization and the new state that is attained is termed Yoga, or union. Having being awakened, the Kundalini balances our energy channels (i.e., the right and left sympathetic nervous system) and brings our attention to the central channel, where a new state of consciousness called "thoughtless awareness" is established. As a result, one finds harmony within as well as with the Cosmos, and the effects of the planets in one's birth chart become neutralized. In one sense, our birth chart completes its purpose and loses its effect on us. The positive qualities and potential skills that were in our birth chart but which we didn't even know that existed within us manifest themselves more visibly while the negative traits and weaknesses are eliminated. That is, one reaches the state of complete inner balance and self knowledge, which is the final point that both astrology and yoga try to bring us to.