These Are the Oldest Photons In the UniverseS

This is the entire view sky as seen from Earth, taken by the Planck observatory during a whole year. In the center, the microwave radiation of our galaxy, the Milky Way. But that's not the important part.

These Are the Oldest Photons In the UniverseS

The image, which has been created using data covering the electromagnetic spectrum from 30 to 857 GHz, shows something more important than our home galaxy. See those yellow dots over dark red? These are the oldest photons in the universe, which scientists believe formed 380,000 years after the Big Bang, when things started to cool and atoms started to form.

These Are the Oldest Photons In the UniverseS

That noise is called Cosmic Microwave Background, "the primordial radiation emitted during the very early stages of the Universe, and its tiny temperature fluctuations, reflecting the seeds from which cosmic structures would later form and subsequently evolve." [ESA]