Planets in the 3rd House
Sun
The Sun in the third house denotes a drive for power in matters regarding mental or analytical accomplishment. The ego and perception of self are motivated by communication, education, relatives and mundane daily activity.
Travel and study are strongly marked in their nature, and they may become impatient if they can't receive a constant flow of mental stimulation and move about freely. This placement may compel the subject to want to learn and to broadly expand their understanding of many varied subjects, and they are likely to remain involved in continuing education and mental development for many years. The ability to express ideas effectively is always important to them, and this placement produces teachers, writers or persons some way involved with enterprises disseminating information. They must however, be cautious becoming intellectually over-confident, as it is easy for one with this position to fall into a pattern of intellectual arrogance, especially when dealing with those less well informed.
Moon
The Moon in the third house projects its influence by giving a studious temperament, especially relating to history, archaeology and subjects generally dealing with the past. The emotions and responses are expressed during mundane daily activities, communication and short distance travel. They have a good memory; their mind is filled with a huge variety of miscellaneous facts and details. They are frequently prone to fantasy and daydreaming. There is a strong intellectual curiosity and an emotional need for continual mental growth.
Mercury
Mercury residing in the third house produces an association with this location, its natural home, the house of the conscious mind. It is good for writing, educational matters, and connecting with relatives. Subjects are not necessarily deep thinkers, but are adaptable, alert and versatile. This placement stimulates matters of the mind, and shows that they are witty and clever, especially in the use of words.
Venus
Venus in the third house suggests a good deal of harmony in early schooling and learning environment. Harmony, peace and love are directed toward relatives, education, writing and short journeys. Artistic and creative, subjects are probably excellent writers. They are socially active, and they operate through persuasion, never through pressure. They get along well with those in their family, and the gift of compromise seems to come naturally to them.
Mars
The Mars third house placement denotes an aggressive, active intellect. Subjects exude power and confidence, and assertiveness or aggression is expressed by verbal or written communication. Their speech is direct and sharp, and they can be argumentative, especially with relatives. They are quick thinking and resourceful, but they sometimes jump to conclusions a little too quickly. In matters of the mind, they are highly competitive. They are always rushed, and they tend to drive too fast, becoming very impatient when caught in traffic.
Jupiter
Jupiter in the third house plays an important part shaping a mentality that is optimistic, philosophic, and spiritually inclined. Expansiveness and optimism are channelled into communication, especially with regard to relatives, short journeys and educational matters. This placement expands the capacity for learning in the fields of philosophy, education, writing, publishing and communication. Their relationship with their siblings and other relatives is very good.
Saturn
Saturn positioned in the third house of mental processes and communication denotes mental discipline and practicality. Limitations, fears and inhibitions are experienced within communication, education and mundane daily routines.
Speech is deliberate and usually well considered, and ideas are practical, judged based on their usefulness and substance. They tell the truth and have a firm sense of right and wrong. This position can often produce feeling of inadequacy and mental depression.
Uranus
Uranus in third house bestows its erratic behaviour in that part of the chart associated with thinking and communicating, as well as early school life endeavours. This dynamic, disruptive individuality is channelled into daily communication, educational concerns and dealings with relatives. It suggests a rebellious nature and wilfulness, especially in the early part of life. They are apt to have frequent upsets in dealing with their siblings, other relatives and acquaintances. They have a very spontaneous mind that may be involved with advanced or new age thinking. Short trips and excursions are rarely planned in advance; the urge just strikes and they go.
Neptune
Neptune in the third house imposes an influence on mental processes and communication with others. Intangibility and sensitivity occur during communication, mundane travel and education. Insecurities in the early part of life are likely, and in their youth, their mind may be subject to drifting and wandering. This placement shows a very intuitive mind, and sometimes, an ability to communicate on a higher plane.
Pluto
Pluto in the third house shows the possibility of disruptive occurrences altering early childhood, family relations and education. Power, control and authority are exerted within communication. They comprehend the deep meaning of communications with others, and they develop very strong and often controversial opinions. These may be either expressed in a very forceful manner or alternatively, they may be totally silent on the subject. They have an almost compulsive need to learn and are likely to be interested in the study of deep and complex matters.
