Searching for Dark Matter
When Astronomers look at the Universe, they study the mysteries of the stars, dust clouds and other matter visible to radio, infrared, optical, ultraviolet, X-ray, or gamma-ray telescopes. What is not readily apparent through these mediums is even more mysterious. When Astronomers observe spiral galaxies like our Milky Way, they use Doppler shifts to determine the rotation speeds of stars and gas at various distances from the center of the galaxy. This allows them to calculate the mass of the galaxy. …
