Planck is Europe's first mission to study the relic radiation from the Big Bang. Ever since the detection of small fluctuations in the temperature of this radiation, announced in late 1992, astronomers have used the fluctuations to understand both the origin of the Universe and the formation of galaxies.
The mission is named after the German physicist Max Planck, whose work on the behaviour of radiation won the Nobel Prize in 1918.
The Planck satellite will observe the cosmic microwave background radiation (CMB). This is the radiation released into the Universe by the Big Bang itself, about 14 thousand million years ago. Since that time, what was once a searing fireball has cooled to become a background sea of microwaves.
Planck will measure the temperature variations across this microwave background with much better sensitivity, angular resolution and frequency range than any previous satellite. The combination of these factors will give astronomers an unprecedented view of our Universe when it was extremely young: just 380 000 years old.
Image Credit: European Space Agency
Credit: European Space Agency