PKS 0405-123

Fingerprinting the Distant Universe Using Light from Quasar PKS 0405-123Using a distant quasar as a cosmic flashlight, a new instrument aboard NASA’s Hubble Space Telescope has begun probing the invisible, skeletal structure of the universe.Called the cosmic web, it is the diffuse, faint gas located in the space between galaxies. More than half of all normal matter resides outside of galaxies. By