ESA’s Planck observatory will observe the Cosmic Microwave Background (CMB). The CMB is the ‘first light’ of the Universe,
released shortly after the Big Bang, about 13 700 million years ago, when light was able to travel freely for the first time. What was once a searing fireball has now cooled to become a background sea of microwaves.
Planck will measure the temperature variations across this microwave background with much higher sensitivity, higher angular resolution and a more extended frequency range than any previous satellite. The combination of these factors will give
astronomers an unprecedented view of our Universe from when it was extremely young: just 380 000 years old.
This picture shows Planck superimposed on a simulated false-colour map of the CMB.