Astronomy

Astronomy is the scientific study of celestial bodies. Stars, galaxies, planets, moons, asteroids, comets and nebulae are studied, as are supernovae explosions, gamma ray bursts, and cosmic microwave background radiation. Astronomy includes the development, physics, chemistry, meteorology and movement of celestial bodies. The big questions are the structure and development of the universe.

Astronomy is one of the oldest sciences. The patterns in the night sky were called constellations by the Arabs. They used the positions of the stars to navigate, and to find when was the best time to plant crops.

Astrophysics is an important part of astronomy. A related subject, cosmology, is concerned with studying the universe as a whole,^[1] and the way the universe changed over time. Astronomy is not the same as astrology, a belief that the motion of the stars and the planets may affect human lives.

There are two main types of astronomy, observational and theoretical astronomy. Observational astronomy uses telescopes and cameras to observe or look at stars, galaxies and other astronomical objects. Theoretical astronomy explains what we see. It predicts what might happen. Observations show whether the predictions work. The main work of astronomy is to explain puzzling features of the universe. For many years the most important issue was the motions of planets. Many other topics are now studied.

Day-time astronomy is possible. First, there's the Sun, but observing directly is dangerous. It is too bright, and can burn your eyes and can cause permanent blindness. To look at the Sun you need proper shields and equipment. Some other individual bright stars and planets can be seen during daylight hours through a telescope or a powerful pair of binoculars.

1. ↑ Unsöld, Albrecht; Baschek, Bodo (2001). Classical Astronomy and the Solar System - Introduction. p. 1.