What is Astronomy?
{{more sources|date=September 2024}} [[File:The Galactic Centre and Bulge above the ESO 3.6-metre telescope.jpg|thumb|The [[Milky Way]] as seen from [[La Silla Observatory]]]] '''Astronomy''' is the [[Science|scientific study]] of [[celestial bodies]]. [[Star]]s, [[Galaxy|galaxies]], [[planet]]s, [[natural satellite|moon]]s, [[asteroid]]s, [[comet]]s and [[nebula]]e are studied, as are [[supernova|supernovae explosions]], [[gamma ray burst]]s, 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 [[science]]s. The patterns of [[stars]] 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,<ref>{{cite book|last1=Unsöld|first1=Albrecht|last2=Baschek |first2=Bodo|title=Classical Astronomy and the Solar System - Introduction|date=2001|page=1}}</ref> 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 [[telescope]]s and [[camera]]s to ''[[wikt:observe|observe]]'' or look at stars, galaxies and other [[astronomical object]]s. 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.