More than 800,000 snapshots from NASA’s Spitzer Space Telescope have been stitched together to create a cosmic tapestry of stars in the Milky Way, spanning an area of sky 120 degrees wide by two degrees tall.
"This is the highest-resolution, largest, most sensitive infrared picture ever taken of our Milky Way," says Sean Carey of NASA's Spitzer Science Centre. "Where previous surveys saw a single source of light, we now see a cluster of stars. With this data, we can learn how massive stars form, map galactic spiral arms and make a better estimate of our galaxy's star-formation rate.”
More than 800,000 frames were stitched together to create this infrared portrait of dust and stars radiating in the inner Milky Way. In this image the mosaic is split up into five components: the far left of the plane (top), the area just left of the galactic centre (second image down), galactic centre (middle) the area just right of the galactic centre (second from bottom) and the far right hand 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. Image: NASA/JPL-Caltech/University of Wisconsin.
Using the Spitzer Space Telescope’s infrared capabilities, astronomers were able to peer through 60,000 light years worth of Milky Way dust, all the way to the other side of the Galaxy, providing a gloriously different perspective of our galactic neighbourhood compared with the somewhat edge-on vista we have from the Earth that appears to condense the Galaxy into a blurry narrow band of light that stretches around the sky.
"I suspect that Spitzer's view of the Galaxy is the best that we'll have for the foreseeable future,” says Barbara Whitney of the Space Science Institute, Madison. “There is currently no mission planned that has both a wide field of view and the sensitivity needed to probe the Milky Way at these infrared wavelengths."
The new mosaic paints a portrait of Milky Way stars through the ages, from stellar embryos, identified by swaths of green organic molecules, to the dusty remnants of dead stars marked out as ghostly translucent orange spheres. In between are bubbles of young stars – yellow and red dots – carved out by the winds of new born starlets blowing away their natal dust, and the blue specks of the older generation stars. Starlight from the Galaxy’s senior population hangs over the central portion of the mosaic as a bluish-white haze.
Over 100 million stars have been catalogued with the Spitzer data, showing the Milky Way as a crowded and highly dynamic place. But we still have a lot to learn, says Spitzer scientist Sean Carey. “I've definitely found a lot of things in this map that I didn't expect to see," he adds.
A high resolution image of the mosaic can be viewed at NASA's Spitzer mission webpage: