The spiral arm segments of the Sunflower galaxy, 37 million light years away, also known as Messier 63, show up in this gorgeous image taken in infrared light by NASA's Spitzer Space Telescope. Infrared light is sensitive to the dust lanes in spiral galaxies, which appear dark in visible-light images. Spitzer's view reveals complex structures that trace the galaxy's spiral arm pattern.
The dust, glowing red in this image, can be traced all the way down into the galaxy's nucleus, forming a ring around the densest region of stars at its center. The dusty patches are where news stars are being born.
The short diagonal line seen on the lower right side of the galaxy's disk is actually a much more distant galaxy, oriented with its edge facing toward us.