Astronomy is one of the oldest sciences and at the same time one of the most modern. Apparently despised until a few years ago, under the assumption that it was considered an activity contemplative and idle around objects that had nothing to do with everyday life, she really did of the affairs of man, to anticipate the events of nature of a cyclical nature, which they allowed his survival: hunting, fishing, agriculture and transportation. By then what matters is practical thinking, like this: Arithmetic for accounting; Geometry for measuring the earth and cubing the grain crops, and the Alphabet to describe it all. Although man in city life does not observe the stars and has moved away from primitive nature, inhabiting a more artificial environment he has entered the era of lunar rockets and satellites. Today is indisputable the importance of this science that has reached the minds of a large sector of the population. The astronomy and neighboring sciences are experiencing a truly explosive growth, which translates, above all, in the increasing number of scientific papers. The interweaving of astronomy with other sciences such as philosophy, physics, meteorology, geology, among others, is increasingly evident.
Just as with the calendars, agriculture will emerge, and with agriculture the first towns appear since 10 thousand BC, thanks to the settlements writing will emerge and with it the empires. Certainly not astronomy was never, not even in the first steps of its evolution, a purely contemplative and useless activity for the practical life of human communities. Astronomical observations entered the process collection and processing of information, useful for the construction of the future, since it is specific to this species as opposed to animals, anticipating events and anticipating future needs in a way aware. The problems of the calendar, of the calculation of the time or of the orientation in the field and at sea, belong to the very foundations of our culture and civilization, and can only be solved by observations of the stars.
Observing the double astronomical and mythological character in the denomination of the days of the week, which in their order are related to the Moon, Mars, Mercury, Jupiter, Venus, Saturn and the Sun (Apollo), we see that the Astronomy had at the first dawn of its history another “utilitarian” application: astrology. According to worldview of then, all nature, including the stars of striking appearance and erratic movement, was animated and was populated by gods, spirits and demons, who definitely influenced the events on Earth such as droughts, floods and earthquakes, and in human events such as wars, plagues and changes of government. The desire to anticipate events, which were considered the designs of the astral divinities, led to the study planetary trajectories carefully, insofar as simple instruments for measuring and Theoretical rudiments of the time allowed it. If they did not have optical devices, nor the development of mathematics, they had simple angle measuring instruments and alignment devices. The series of observations thus obtained over centuries and even millennia eventually led to values fairly accurate numerics. Especially advanced was the knowledge of the length of the year linked to the seasons, from the month to the lunar cycle and from the week to the lunar phases, as of course the periods of the movements of the planets. At this stage in the development of astronomy there was not yet any concern by the theoretical explanation of the movement of the stars.