Spiral galaxies make beautiful targets in the infrared. Dust, normally opaque and dark in visible light, comes alive in the IR. M66 is a bright, nearby, barred spiral galaxy. In this Spitzer image, the arms of the galaxy are littered with dust, formed when stars are born and when they die. This happens primarily in the spiral arms, which is why the cold dust there is obvious (seen here in red). The inner region of the galaxy is very old, and star formation there ceased ages ago.
At 35 million light years away, M66 is an easy target for small telescopes, and is one of the best-studied galaxies in the sky. But images like this from Spitzer provide new insights into how galaxies form and maintain their shape. In astronomy, there's no such thing as "having seen it all". Whenever new eyes are used to peer upwards, we learn new things.Original blog postOriginal press releaseImage credit: NASA/JPL-Caltech/R. Kennicutt (University of Arizona) and the SINGS Team