Why is spectroscopy so important in astronomy?
Astronomy is rather unusual among the sciences in that it is almost entirely observational rather than experimental. With the rare exception of a few meteorites and samples of moon rock, just about everything we know about the universe and the objects in it comes from analysing the light (and similar electromagnetic radiation such as radio and X rays) coming from it. Spectroscopy is a key tool in this process, revealing the physical and chemical processes which drive the formation, structure and evolution of the components of our universe.
