Credit: NASA/JPL-Caltech/A. Kashlinsky (Goddard Space Flight Center)

The top panel is an image from NASA's Spitzer Space Telescope of stars and galaxies in the constellation Draco, covering about 50 by 100 million light-years (6 to 12 arcminutes). This is an infrared image showing wavelengths of 3.6 microns, below what the human eye can detect. The bottom panel is the resulting image after all the stars, galaxies and artifacts were masked out. The remaining background has been enhanced to reveal a glow that is not attributed to galaxies or stars. This might be the glow of the first stars in the universe.