NASA's infrared Spitzer satellite has released these gorgeous new images of the Andromeda galaxy. In infrared, you are directly observing the dust lanes that describe the galactic arms, rather than simply looking at reflected starlight.
Here's a bigger version. Lyman Spitzer, after whom the telescope is named, was one of the primary movers behind the original Space Telescope idea, which eventually grew into the Hubble Space Telescope. He was also my grand-advisor: George Field was my Ph.D. advisor, and Spitzer was his.
