Astronomers analyze the spectrum of light coming from different stars to determine what they are made of. Create your own spectrometer to see the difference in the spectrums of light around you. A simple spectrometer can be built from a CD and a cereal box. Cut a slit on one side of the box and place the CD on the other side with about a 60 degree angle and look down into the opening of the box. The slit should not be too wide, otherwise the spectrum lines will be blurred. Happy making!