«This evidence opens up a new phase in the study of the primordial Universe». This is how Carlo Baccigalupi and Luigi Danese of the Astrophysics and Cosmology group of SISSA comment the results published on 17 July relating to the final analyses on the data from the Planck satellite, to which the scientists of the School made a fundamental contribution. In this research, the polarized signal of the Cosmic Microwave Background Radiation in the whole sky was revealed for the first time, opening up a new chapter in understanding the Universe thanks to this fundamental tracer. This signal is produced by the ancient light “bouncing” on the charged particles freed from the first structures in formation: it could contain the imprint of gravitational waves produced fractions of a second after the Big Bang. This discovery would be a new revolutionary observation channel of that huge initial explosion and of the still unknown physics processes of the highest energies occurred fractions of a second after the explosion. SISSA researchers say that the results of Planck «shake the very foundation of basic principle knowledge in Astrophysics, Cosmology and Physics of the Particles and show that this research is now possible. It has already permitted the drawing, construction and gathering of data of scores of observatories on Earth, in the Stratosphere and in Space, in charge of investigating new scenarios explored by Planck».