Astronomy is the scientific research of heavenly objects (such as stars, comets, planets, and galaxies) and phenomena that originate outside the Earth's atmosphere (such as the background of the cosmic radiation) it refers to the evolution, physics, chemistry, meteorology, and motion of celestial objects, as well as design and development of the universe.
Astronomy is one of the oldest Sciences.Astronomers of early civilizations performed methodical observations of the night sky and established astronomical artifacts from many earlier. However, the invention of the telescope is required before astronomy was able to become a world-class. Historically astronomy is included as different disciplines astrometry, celestial navigation, astronomy observations, calendars, and even professional astronomy Astrology, but today is often considered a synonym of Astrophysics.
After the 20th century the area of professional astronomy and theoretical branches divide observations. Observations astronomy is aimed at obtaining and analyzing data, mainly with the basic principles of physics. Theoretical astronomy is aimed at the development of the computer or analytical models to describe astronomical events.The two fields complement each other, with theoretical astronomy, seeking to explain the results and observations, observations, used to confirm theoretical results.
Amateurs have contributed to many important astronomical discoveries and astronomy is one of several studies, where amateurs can still play an active role, particularly in the discovery and observation of transient phenomena.
Old or even ancient astronomy should not be confused with Astrology, the system of belief that human activities are correlated with the positions of celestial objects. Although the two fields share common origin and part of its methods (namely, the use of ephemerides), they differ.