Figure 3-37 Views of the Milky Way’s Central Regions (a) and (b) Infrared radiation can travel through media that block visible light. (c) An optical image in the direction of Sagittarius, toward the Milky Way’s center, showing many nearby stars. The dark regions are interstellar gas and dust clouds that prevent visible light from beyond them from reaching us. (d) An infrared image of the same area of the sky, showing many more distant stars whose infrared radiation passes through the clouds and is collected by our telescopes.