Infrared Portrait of the Inner Milky Way Galaxy Postcard

This is one segment of an infrared portrait of dust and stars radiating in the inner Milky Way. More than 800,000 frames from NASA's Spitzer Space Telescope were stitched together to create the full image, capturing more than 50 percent of our entire galaxy. As inhabitants of a flat galactic disc, Earth and its solar system have an edge-on view of their host galaxy, like looking at a glass dish from its edge. From our perspective, most of the galaxy is condensed into a blurry narrow band of light that stretches completely around the sky, also known as the galactic plane. This segment extends through the constellation Scorpius. The only significant feature seen here that also is evident in visible light is the Cat's Paw Nebula, or NGC 6334, at the upper left. The flat band of green running through this region is mostly dust in the distant disc of the Milky Way galaxy. In visible light the foreground dust renders this area nearly featureless and dark with only a scattering of nearby stars. The swaths of green represent organic molecules, called polycyclic aromatic hydrocarbons, which are illuminated by light from nearby star formation, while the thermal emission, or heat, from warm dust is rendered in red. Star-forming regions appear as swirls of red and yellow, where the warm dust overlaps with the glowing organic molecules. The blue specks sprinkled throughout the photograph are Milky Way stars. This survey segment spans galactic longitudes of 343.5 to 351.7 degrees and is centred at a galactic latitude of 0 degrees. It covers about two vertical degrees of the galactic plane. This is a three-colour composite that shows infrared observations from two Spitzer instruments. Blue represents 3.6-micron light and green shows light of 8 microns, both captured by Spitzer's infrared array camera. Red is 24-micron light detected by Spitzer's multiband imaging photometer. This combines observations from the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) and MIPSGAL projects. http://commons.wikimedia.org/wiki/File:GLIMPSE-MIPSGAL_Milky_Way_10.jpg