Astronomy

Astronomy (from the Greek words astro(αστέρι) = star and nomos(νόμος) = law) is the scientific study of celestial objects (such as star, planet, comet, and galaxies) and phenomena that originate outside the Earth's atmosphere (such as the cosmic background radiation). It is concerned with the evolution, physics, chemistry, meteorology, and motion of celestial objects, as well as the formation and development of the universe. Astronomy is one of the oldest sciences. Astronomers of early civilizations performed methodical observations of the night sky, and astronomical artifacts have been found from much earlier periods. However, the invention of the telescope was required before astronomy was able to develop into a modern science. Historically, astronomy has included disciplines as diverse as astrometry, celestial navigation, observational astronomy, the making of calendar, and even astrology, but professional astronomy is nowadays often considered to be synonymous with astrophysics...