How powerful is spectroscopy?
Spectroscopy has revealed the expansion of the Universe, the chemical composition of stars and nebulae, and the existence of exoplanets.
Taking the spectrum of a single astronomical object used to be a very time-consuming process. But with the advent of sensitive electronic detectors and ingenious multi-object spectrographs, spectroscopy has become a much more powerful technique. The latest generation of instruments can even provide spectral information for every single pixel of an astronomical image. Astronomers expect spectroscopy to detect biosignatures – possible indicators of biological activity – in the atmospheres of Earth-like exoplanets.
A selfie made by your friend may look nice, but their DNA can tell you more about her. Likewise, the spectrum of a star or galaxy contains more information than a beautiful photograph.