Images from the NASA Spitzer Space Telescope have been used to create a staggering 20-gigapixel panorama, encompassing more than half of the galaxy’s stars. The vista was created from more than a decade’s worth of infrared images, and will be used to help further our understanding of the structure and formation of stars in the Milky Way.
The Spitzer Space Telescope was launched in August 2003. Since that time astronomers have spent more than 4,000 hours imaging the Milky Way in infrared, a light form that lies between the visible and microwave portions of the electromagnetic spectrum. The effort is known as the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire, or GLIMPSE for short.
The 360-degree mosaic, which was presented at the TED 2014 Conference in Vancouver, Canada last week, is compiled from more than 2 million individual infrared images taken by the telescope. It is the first time that the snaps have been stitched together into a single image.
“If we actually printed this out, we’d need a billboard as big as the Rose Bowl Stadium to display it," said Robert Hurt, an imaging specialist at NASA's Spitzer Space Science Center in California. "Instead we've created a digital viewer that anyone, even astronomers, can use."
Though the image is undeniably huge, it actually only shows around three percent of the sky. However, due to the image’s focus on the dense flat plane of our home galaxy’s spiral disk structure, it actually captures more than half of the Milky Way’s stars.
A similar image was taken by the Visible and Infrared Survey Telescope for Astronomy (VISTA) in 2012, though it has a more modest 9-gigapixel resolution. Both the Spitzer and VISTA images studied the infrared part of the spectrum, which is able to penetrate the clouds of dust that obscure sections of the galaxy when viewed in visible light.
"Spitzer is helping us determine where the edge of the galaxy lies," said Ed Churchwell, co-leader of the GLIMPSE team. "We are mapping the placement of the spiral arms and tracing the shape of the galaxy."
The new image will not only be used to help scientists map both the structure of the Milky Way and star formation within it, but will also significantly aid one of NASA’s future projects. The 360-degree panorama will be used to help pinpoint the most interesting areas of the galaxy, which will then be studied by the James Webb Space Telescope, due to launch in 2018.
The Spitzer panorama can be viewed on Caltech's Spitzer website by means of the Microsoft WorldWide Telescope virtualization platform.