PIX4646038: Satellite Planck. Illustration - Artist's view of the European satellite Planck separating from the upper floor of the Ariane V rocket, 30 minutes after its launch. This satellite measures temperature fluctuations in the fossil radiation of the primordial universe. Planck separates from upper stage. Planck separated from the launcher about 30 minutes after launch, a couple of minutes after Herschel. The two spacecraft independently headed towards their respective orbits around the second Lagrange point of the Sun - Earth system (L2), some 1.5 million km from Earth in the direction opposite to the Sun. Planck is the first european mission to study the relic radiation from the Big Bang. Ever since the detection of small fluctuations in the temperature of this radiation, called Cosmic Microwave Background, astronomers have used the fluctuations to understand both the origin of the Universe and the formation of galaxies / Bridgeman Images