Map of the cosmic microwave background
author: Nasa/Novapix
reference: a-uni01-70001
Image Size 300 DPI: 20 * 15 cm
Microwave image of the entire sky. This historic all-sky map is based on the first two years of data from NASA's COsmic Background Explorer (COBE) satellite. After computer processing to remove contributions from nearby objects and the effects of the earth's motion, the map shows temperature variations in the early Universe. In blue is the main background radiation (2.73 degrees Kelvin); the red spots are warmer, oldest, and most distant structures known. As our Universe expanded and cooled, conglomerations of mass formed. The COBE images confirm that only a million years after the big-bang, which occurred roughly 15 billion years ago, parts of the universe were visibly hotter than other parts.