Longer and weaker waves are represented at the bottom of the pyramid while stronger and shorter wavelengths are depicted at the top.  These waves include radio and infrared and UV and gamma or x-rays, respectively.  In the field of astronomy these wavelengths are important in determining composition, speed, and proximity of both stars and planets.    Here, the tactics used by astronomers to unlock the mysteries of the universe will be explored.  In order to understand how astronomers use the information they gather from radiation, it is important to know how and what they collect.  Follow the pages that explore what spectra is and how it can be measured for a more thorough explanation of the data collected by scientists in the field of astronomy.  Next, choose either stellar or galaxy spectra to learn more about the universe around us.




                                                                                                                                                                       
                                                             What is spectra?                                                                                                                How can it be measured?