Stars and planets, the objects of the external Space (Universe), are responsible for the programming of your sub-conscious mind at Manomaya Kosha. This creates the life you are experiencing now. Your purpose of life, your goals, your choices, inborn habits, inclinations of mind, your reference points of happiness and pain, your own philosophy of how you lead your life, are some part of that programming, among many more.
The movement of the stars and planets in their respective trajectories act as a Cosmic Clock for timing the events in your life and programming your sub-conscious mind. Man understood this secret 12000 years ago. Since then, he has been studying stars, planets, and their movements in order to understand the core (or true) purpose of his being on this planet. This has helped him manifest his core desire and experience the eternal joy by focusing his attention and energies on his 'true purpose' only.
Man has understood this fact very well that the cause of misery and pain lies in deviation from his core purpose. And to keep himself aligned, man has been observing the stars for ages. That is also how the development of Hindu Astrological System ('Jyotish') initiated.
The word 'Jyotish' means "Illuminated Divine Lights Showing the True Path". The word 'Religion' means "Getting Aligned Again". In Hindu Astrology, the Moon stands for the sub-conscious mind. Whereas, Mercury is considered to stand for the ordinary conscious mind with analytical and reasoning faculties. Only in Hindu Astrology, the timing of events is worked out from position of the Moon at birth time. When the Moon is studied for seconds, minutes and degrees (120° for 120 years), then a certain combination of planets gives accurate timing of events. This calculation goes up to the accuracy of an hour for happening of an event in one's life. This system is known as 120 year situation method (Vimshottari Dasha Padhhati), given by eminent Hindu astrologer Sage Parashar In 5th Century B.C.
Hindu mystics decoded the mystery of life thousands of years ago. The most amazing part is that they mathematically derived the process of evolution for an individual based on planetary positions at birth, their transits and their programming for sub-conscious mind. More into this understanding is working evolution of Chakras with position of planets in the birth chart of an individual. In the application of MahaVastu™, the birth chart is studied from this angle. The design of building is then decided. Each individual horoscope is unique with its own purpose on the planet. Even Greeks in the past studied horoscopes with this thought in mind. So that by defining one's purpose, structures can be made to perform the desired function.