Spiral galaxies like Milky Way bigger than thought, says CU-Boulder study
University of Colorado Boulder said:
CU-Boulder Professor John Stocke, study leader, said new observations with Hubbleís $70 million Cosmic Origins Spectrograph, or COS, designed by CU-Boulder show that normal spiral galaxies are surrounded by halos of gas that can extend to over 1 million light-years in diameter. The current estimated diameter of the Milky Way, for example, is about 100,000 light-years. One light-year is roughly 6 trillion miles.