The centerpiece of this HST image is a giant cluster of about 3,000 stars called Westerlund 2. The cluster resides in a stellar breeding ground known as Gum 29, located 20,000 light-years away from Earth. Hubble's Wide Field Camera 3 pierced through the dusty veil shrouding the stellar nursery in near-infrared light, giving astronomers a clear view of the nebula and the dense concentration of stars in the central cluster. The cluster measures between 6 to 13 light-years across, is only about 2 million years old and contains some of our galaxy's hottest, brightest, and most massive stars. The red dots scattered throughout the landscape are a rich population of newly forming stars still wrapped in their gas-and-dust cocoons. The image's central region, which contains the star cluster, blends visible-light data taken by Hubble's Advanced Camera for Surveys with near-infrared exposures taken by the Wide Field Camera 3. The surrounding region is composed of visible-light observations taken by the Advanced Camera for Surveys. The red colors in the nebulosity represent hydrogen; the bluish-green hues are predominantly oxygen.