One of the most prolific stellar nurseries in our Milky Way galaxy is a nebula known as RCW 49. It is exposed in superb detail for the first time in this image from NASA's Spitzer Space Telescope. Located 13,700 light-years away in the southern constellation Centaurus, RCW 49 is a dark and dusty star factory that houses more than 2,200 stars. Because many of the stars in RCW 49 are deeply embedded in plumes of dust, they cannot be seen at visible wavelengths. But when viewed with Spitzer's infrared cameras, RCW 49 becomes transparent, making the stars visible.