What Is Spectroscopy?
Astronomical telescopes are famous for the images captured by their cameras, but they often also rely on instruments called spectrographs. Spectrographs — sometimes called spectroscopes or spectrometers — don’t produce beautiful images; their data is expressed as a jagged line on a chart. It doesn’t look like much, but it’s how telescopes like Webb will reveal details of atmospheres on other planets, the composition of stars, the motion of galaxies, and more.
A spectrograph breaks the light from a single object into its component colors the way a prism splits white light into a rainbow, allowing scientists to analyze the light and discover properties of the object emitting it.