Chandra X-ray Image of Galactic Ridge
This extremely deep Chandra X-ray Observatory image has resolved a long-standing mystery about an X-ray glow along the plane of the Milky Way. The Chandra results show that the X-ray emission in the region is caused by hundreds of point-like sources, implying that the glow along the plane of the Galaxy is due to millions of such sources.
(Credit: NASA/CXC/TUM/M.Revnivtsev et al.)

Spitzer Infrared Image of Galactic Center
This infrared image from the Spitzer Space Telescope shows hundreds of thousands of stars crowded into the swirling core of our spiral Milky Way galaxy. In visible-light pictures, this region cannot be seen at all because dust lying between Earth and the galactic center blocks our view. The plane of the Milky Way's flat disk is apparent as the main, horizontal band of clouds. The brightest white spot in the middle is the very center of the galaxy, which also marks the site of a supermassive black hole.
More at http://www.spitzer.caltech.edu
(Credit: NASA/JPL-Caltech/GLIMPSE Team)

Galactic X-ray Ridge with Scale Bar
(Credit: X-ray (NASA/CXC/TUM/M.Revnivtsev et al.); IR (NASA/JPL-Caltech/GLIMPSE Team)