Crash Course Astronomy: Galaxies, Part II

Can a sequel be better than the original? When it comes to Star Trek II: The Wrath of Khan, yes. And when it comes to an episode of Crash Course Astronomy about galaxies, then judge for yourself: In this second part I go over active galaxies--ones pouring out huge amounts of energy, making them so extremely bright they can be seen for billions of light years. For several years I worked on the NASA education and public outreach programs for astronomical satellites like Swift, Fermi, NuSTAR, and o...