Cosmic microwave background. Whole sky image of the cosmic microwave background made by the MAP (Microwave Anisotropy Probe) spacecraft. This map indicates that the age of the universe is around 13.7 billion years. The data also reveal that the universe is expanding at 71 kilometres per second per megaparsec (1 Mpc = 3262 light years). The colours reveal variations in the temperature of the universe in all directions. This correlates to the density of material at the time when the universe became transparent to radiation, about 380,000 years after its creation. The denser regions (red, yellow) formed the seeds of galaxies and other structures. Data obtained in 2003.