X-Shaped Bulge in the Milky Way

In 2010, NASA's Wide-field Infrared Survey Explorer (WISE) mission observed the entire sky twice. Astronomers used these data to point out the X-shaped structure in the bulge of the Milky Way, contained in the small circle at center, as well as the inset image. The circled central portion covers roughly the area of sky that would be blocked by a basketball when held out at arm's length. Dustin Lang, an astronomer at the Dunlap Institute of the University of Toronto, used these data to make this map, which shows the full 360-degree panorama of the sky as seen by WISE. Lang collaborated with Melissa Ness, postdoctoral researcher at the Max Planck Institute for Astronomy in Germany, http://photojournal.jpl.nasa.gov/catalog/PIA20699