Created from the Galactic Legacy Mid-Plane Survey Extraordinaire (Glimpse) project, it's the most comprehensive visual map of the Milky Way Galaxy released to date -- and yet it only shows just over half of the galaxy's stars. Stitched together from more than 2 million images taken by the Spitzer Space Telescope over the course of a decade, the zoomable, 360-degree image comes in at 20 gigapixels. Since its launch in 2003, Spitzer has spent a total of 4,142 hours taking pictures of the Milky Way in infrared light.
"If we actually printed this out, we'd need a billboard as big as the Rose Bowl Stadium to display it," Spitzer Space Science Center imaging specialist Robert Hurt said in a statement. "Instead we've created a digital viewer that anyone, even astronomers, can use."
When viewed in the visual spectrum, sections of the Milky Way -- a flat spiral disc -- are occluded by dust. By taking images in the infrared spectrum, through which stars can be seen through the dust, Spitzer allows us a more complete picture of our galaxy so that astronomers can map the spiral arms and determine the galaxy's edges.
With Glimpse data, astronomers have been able to create the most accurate map of our galaxy's center to date, and see star formation and faint stars in the outer, darker regions that, prior to Spitzer, were unexplored territory.
"There are a whole lot more lower-mass stars seen now with Spitzer on a large scale, allowing for a grand study," said Barbara Whitney of the University of Wisconsin, Madison, co-leader of the Glimpse team. "Spitzer is sensitive enough to pick these up and light up the entire 'countryside' with star formation."
There are two ways to view the mosaic: using Microsoft's WorldWide Telescope platform, which includes context and cross-fade to visual light; and CDA Aladin Lite, which doesn't show the entire mosaic, but instead offers shortcuts to regions of interest, such as nebulae, and image exports.
The Glimpse data is also being used as part of a NASA citizen scientist project. People can visit the Milky Way Project Web site and help NASA catalogue areas of interest, such as bubbles, clusters, and galaxies.