This is a map of oldest light in our universe. It is derived from data detected with the greatest precision yet by the Planck mission. The ancient photons, also called the cosmic microwave background, give us a view of the universe when it was about 370,000 years old. The variations are related to the tiny temperature fluctuations caused by regions of slightly different densities—the seeds of all the future structure of the Universe—the stars, galaxies, and life existing today.
Planck is a European Space Agency mission with significant participation from NASA’s Jet Propulsion Laboratory.
Image Credit: ESA