More than 800,000 frames from NASA's Spitzer Space Telescope were stitched
together to create this infrared portrait of dust and stars radiating in
the inner Milky Way.
As inhabitants of a flat galactic disk, 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.
In this mosaic the galactic plane is broken up into five components: the
far-left side of the plane (top image); the area just left of the galactic
center (second to top); galactic center (middle); the area to the right of
galactic center (second to bottom); and the far-right side of the plane
(bottom). From Earth, the top two panels are visible to the northern
hemisphere, and the bottom two images to the southern hemisphere.
Together, these panels represent more than 50 percent of our entire Milky
Way galaxy.
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. The bluish-white
haze that hovers heavily in the middle panel is starlight from the older
stellar population towards the center of the galaxy.
This is a three-color 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.
The Galactic Legacy Infrared Mid-Plane Survey Extraordinaire team
(GLIMPSE) used the telescope's infrared array camera to see light from
newborn stars, old stars and polycyclic aromatic hydrocarbons. A second
group, the Multiband Imaging Photometer for Spitzer Galactic Plane Survey
team (MIPSGAL), imaged dust in the inner galaxy with Spitzer's multiband
imaging photometer.
