There’s a light that fills the whole Universe. It’s the oldest light, the first radiation to travel freely across the Cosmos. It is named the cosmic microwave background radiation and, as a fossil, it is an image from the past, with information about the origins and up to the first galaxies.
Article by Elsa Teixeira, in partnership with National Geographic Portugal.
Full article (in Portuguese) and on the National Geographic Portugal website (in Portuguese)