Scientists use a spectroscope to receive the image of a spectra of light coming from faraway stars. Spectra is sometimes considered to be the fingerprint of the elements, with each elements having different spectra.
Step-by-step explanation:
They do this by examining the spectrum of light from a star. When an ingredient is inspired, it gives off the light in distinct wavelengths, or colors.
The spectra of the Sun and stars presented bright and dark lines called Fraunhofer lines. Those were shown to be generated by elements transmitting or receiving light at specific wavelengths. Because each element emits or absorbs light only at specific wavelengths, the chemical distribution of stars can be resolved.