... Images of the star forming region W5 like those in the infrared by NASA's Wide Field Infrared Survey Explorer (WISE) satellite provide clear clues with indications that massive stars near the center of empty cavities are older than stars near the edges. ... Here, a high concentration of dust and molecular gas absorb practically all the visible light emitted from background stars. ... The field of view spans the Andromeda Galaxy (M31), a massive spiral a mere 2.5 million light-years away. ...