The Sun - Ruler of Leo: The sign that the sun is in indicates: 1) what kinds of experiences help to strengthen and clarify your self-image, and 2) what unconscious biases shape your view of the world.
The house that the sun occupies is where you want to shine and where you can find and expand your personal power.
The Moon - Ruler of Cancer: The sign that the moon is in indicates: 1)what kind of experiences are most essential to your happiness; 2) what unconscious emotional needs motivate your behavior; and 3) how moodiness and irrationality are expressed.
The house that the moon occupies is where you are most subject to emotional ups and downs.
Mercury - Ruler of Gemini & Virgo: The sign that Mercury is in indicates what your intellectual and communicative strengths and weaknesses are.
The house that Mercury occupies is where you communicate best.
Venus - Ruler of Libra & Taurus: The sign that Venus is in indicates: 1) what you need in a partner; 2) what you can bring to a relationship; and 3) how you can calm down.
The house that Venus occupies signifies what you really enjoy.
Mars - Ruler of Aries & Scorpio: The sign that Mars is in indicates: 1) what battles you must face; 2) how you can sharpen your will; and 3) how you express aggressiveness.
The house that Mars occupies is where you expend the greatest energy and where you must be more assertive to avoid pointless conflict and strife.
Jupiter - Ruler of Sagittarius & Pisces: The sign that Jupiter is in indicates what kind of experiences will help you feel more faith in yourself and in life.
The house that Jupiter occupies is where you often have good fortune and like to spend leisure time. It is also where you may be taking too much for granted.
Saturn - Ruler of Capricorn & Aquarius: The house that Saturn occupies is: 1)where you must learn to act alone; 2) where a lack of self-discipline will lead most quickly to sorrow; 3) where you feel least secure and tend to overcompensate; and 4) where your ability to dream and have faith will be most severely tested.
The expression of these seven planets in relation to each other formed the foundation of astrology. The active mechanism of their expression, that is the energy that affects change, is the equivalent of what Lucas termed "The Force". Hence he wanted the main characters in the original film to personify the seven planets of the zodiac with their interactions with each other acting as the driving force behind the story.
Luke: The sun rules will power and ego. It is the core of your potential and uniqueness as an individual; who you are and what you are about. It represents the main direction and focus you want your life to take, and your determination to accomplish what you set out to do. It is your personal honesty and integrity, and the ability to command respect and authority, to impress and influence others.Think of Luke's conversation with Owen Lars.
R2-D2: The moon rules desire as opposed to ego, need as opposed to expediency or reason. It describes how you feel about yourself, how you handle relationships, and how you emotionally respond to situations and experiences. It describes the flow of your daily functions; physical, emotional, and mental. The moon is your emotional or experiential memory. Note that the two planets that represent memory and recall are the only two characters present in all 6 films with R2's memory being completely in tact. Think about R2's determination to find Ben Kenobi.
C3PO: Mercury indicates mental outlook, intellectual endeavors, the way you think and communicate. It represents ideas, methods, and information. It rules your hands and thus your manual dexterity and mechanical skills. Mercury also describes transportation; that is, how you get where you're going physically and mentally. Do you speed with all possible haste or amble along taking a few detours here and there?
Just think about the first 20 minutes of the movie. Beginning through R2 and 3PO splitting up on Tatooine.
Leia: Venus rules your social attitudes and behavior, and your aesthetic tastes and inclinations. It is female relationships and social interactions at every level. Venus indicates your values. It describes romance, marriage and other partnerships, capacity for humor, and the pursuit of pleasure. Leia on the Death Star.
Han: Mars rules physical energy and efforts. It describes the strength and direction of the physical force that drives your ego, fires your emotions, and encourages your mental endeavors and communicative skills. It describes male relationships and associations, risk-taking inclinations, and the physical challenges you are likely to encounter....yeah everyone gets this one.
Obi-Won: Jupiter rules your potential for growth and expansion on many levels; physical, intellectual, spiritual, cultural, and the accumulation of material assets, power, and status. It describes your optimism and aspirations. It represents your father and his position in society. obviously Obi's relationship with Luke.
Vader: Saturn rules responsibilities, restrictions and limitations you are apt to encounter, and the lessons you must learn in life. It does not deny or diminish imagination, inspiration, spirituality, and good fortune but it does demand that these things be given structure and meaning. thus the reason Luke must come to know the force.