The Universe's First Fireworks
This image reveals a background glow of light from a period of time when the universe was less than one billion years old. This light most likely originated from the universe's very first groups of objects -- either huge stars or voracious black holes.
The image from NASA's Spitzer Space Telescope shows a region of sky in the Ursa Major constellation. To create this image, stars, galaxies and other sources were masked out. This infrared image covers a region of space so large that light would take up to 100 million years to travel across it. Darker shades in the image on the left correspond to dimmer parts of the background glow, while yellow and white show the brightest light.