The iconic Whirlpool Galaxy M51a (NGC 5194) and its companion M51b (NGC 5195) in infrared. I used the same bands as the Cygnus mosaic. The result interests me because it looks similar in coloration to a visible light image, which is not something I expected. Though the colors are similar, the structure is of course very different looking since we are seeing dust. To me it is kind of like looking at the skeleton of a galaxy.
Some green halos are apparent due to the WISE data being quite a bit lower in resolution than the Spitzer IRAC4 data.
Red: Spitzer/MIPS24 (24μm)
Green: WISE/W3 (12μm)
Blue: Spitzer/IRAC4 (8μm)
North is up.