The impact that spectroscopy and light has had on the world has not been recognized enough. The discovery of spectroscopy has allowed us to know so much more about astronomy and what makes up our universe. Spectroscopy is the investigation and measurement of spectra when matter interacts with electromagnetic radiation. In astronomy, we look at how light from an astronomical source interacts with different objects to form a spectra of light. There are three different kinds of spectra, a continuous spectrum, an emission spectrum, or an absorption spectrum. In a continuous spectrum, a hot light source produces light of all visible wavelengths. The spectrum shows a smooth, continuous rainbow of light. In an emission spectrum, the atoms in a warm cloud emit specific wavelengths of light. On the spectrum, we see bright emission lines at specific wavelengths on a black background. In an absorption spectrum, light from a hot source passes through a cloud of cooler gas. Atoms in the cloud absorb some of the wavelengths of light. In the spectrum, we see dark absorption lines on a continuous rainbow background. Each spectrum of an element or molecule is unique, like a fingerprint, allowing astronomers to recognize them easily. Through studying light, astronomers are allowed to determine the chemical composition of the Sun and other stars, the temperature of an object, the color of an object, and if the object is moving towards or away from us.