Planck was ESA’s mission to observe the first light in the Universe. Planck was selected in 1995 as the third Medium-Sized Mission (M3) of ESA’s Horizon 2000 Scientific Programme, and later became part of its Cosmic Vision Programme. It was designed to image the temperature and polarization anisotropies of the Cosmic Background Radiation Field over the whole sky, with unprecedented sensitivity and angular resolution. Planck is testing theories of the early universe and the origin of cosmic structure and providing a major source of information relevant to many cosmological and astrophysical issues.
