A deep study of 29 gigantic blobs of hydrogen gas has been carried out with NASA's Chandra X-ray Observatory to identify the source of immense energy required to illuminate these structures. These mysterious blobs - called "Lyman-alpha blobs" by astronomers because of the light they emit - are several hundred thousand light years across and are seen when the Universe is only about two billion years old, or about 15% of its current age.

One of the most impressive accomplishments of the Chandra mission has been the improved understanding of the distant X-ray Universe. Chandra has accomplished this through deep X-ray surveys that generally involve pointing Chandra at a particular region of the sky that is not known to have any bright nearby objects and letting the camera collect X-ray light for an extended period of time.