... This wide, detailed Spitzer Space Telescope view features infrared light from dust (red) and old stars (blue) in Andromeda, a massive spiral galaxy a mere 2.5 million light-years away. In fact, with over twice the diameter of our own Milky Way, Andromeda is the largest nearby galaxy. ... Also known as Abell 2151, this cluster is loaded with gas and dust rich, star-forming spiral galaxies but has relatively few elliptical galaxies, which lack gas and dust and the associated newborn stars. ...