The Super Spectrum
By William Vigo And Amanda Detmar-Salazar
How to Identify Elements in Space!
In outer space there are many elements. Each element has its own finger print in a form of certain wave lengths that emit and absorb light. In order to find out what element is which you would use a spectroscope and see the colors that would match the element.
You can tell this is hydrogen by its unique wave length. What you see is a small part of the hydrogen emission spectrum.