X-Rays from the Galactic Plane . ... CXC , NASA Explanation: In February 2000, the orbiting Chandra X-ray Observatory spent 27 hours staring into the plane of our Milky Way galaxy . Its target was a spot in the small constellation Scutum , within the Milky Way's zone of avoidance where galactic gas and dust clouds block visible light, making a poor window for optical telescopes. ... Intriguing is the diffuse blue glow of high energy x-rays, distinct from the individual sources in the picture. ...