Cosmic microwave background. MAP (Microwave Anisotropy Probe) spacecraft whole sky image of the cosmic microwave background. This image uses data obtained in 2003, 2004 and 2005. 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 formtion. The denser regions (red, yellow) formed the seeds of galaxies and other structures. The white lines show the polarisation direction of the oldest light.