Astronomy is the science that studies the Universe. It is, perhaps, one of the oldest Sciences on earth. The word "astronomy" comes from two Greek words: "Astron" star, the sun and NOMOS - law. Thus, this word means "law of the stars".
Over the years, thousands of years has been observed in the sky, accumulating astronomical knowledge. The level of development of astronomy was high already in ancient times. Scientists knew many of the constellations were able to calculate the time of sunrise and sunset, moon, planets, major stars, to predict lunar and solar eclipses. This knowledge and observations helped hunters to find their way to his camp, sailors to navigate in the sea. With the predictions of the change of the seasons were related to agricultural work. On the celestial bodies were the expense of time, was the calendars. The stars foretold destiny.
Now you do not need to determine the ship's course by the stars, to predict floods or read the time on the Sands of the hourglass. Replaced astronomy came here technical means. But astronomy and Astronautics still indispensable in communication systems and television, observations of the Earth from space.
Astronomy is closely related to other Sciences, especially physics and mathematics, methods are widely in use. Astronomy as a science is based primarily on the observations. Unlike physicists, astronomers are deprived of the opportunity to experiment over the objects of their research. Almost all the information about celestial bodies brings us their electromagnetic radiation. Only in the last 40 years, some celestial body began to study directly: using automatic stations has become possible to probe the atmospheres of planets, to study their soil.
Therefore, in the XX century astronomy was divided into two main branches: observational and theoretical. The purpose of observational astronomy - obtaining data from observations of the heavenly bodies. These data, the astronomers then analyzed using basic laws of physics. Astronomers-theorists engaged in the development of computer, mathematical or analytical models to describe astronomical objects and phenomena. These two branches are complementary: theoretical astronomy seeking to explain the results of observations and observational astronomy is used to confirm the theoretical findings and hypotheses.
Astronomy studies the fundamental laws of nature and of our world. Therefore, it is especially great philosophical importance. In fact, it defines our worldview.