Current experiments use high-energy particle collisions to study how the elementary particles of matter, quarks, come together to form the nuclei of atoms. The collision between an electron and a nucleus – in research pursued by the INFN collaboration at the Jefferson Lab – will provide a three-dimensional image of the inside of the nucleus while collisions between lead nuclei – at CERN in Geneva – can, for a short instance, produce a bubble of quark-gluon plasma, the primordial state of matter. The formation of the stars, which only appeared as the universe expanded and cooled, is the subject of research at the INFN’s national laboratories. At the Gran Sasso national laboratory, for instance, the small LUNA accelerator is used to study the formation of nuclei with energies comparable to those of stars, which are much lower than the energies obtained with normal particle accelerators. The Legnaro and Southern national laboratories house some of the most advanced accelerators and detectors in the world, which are used to produce and study the characteristics of unstable nuclei. One of the main aims of these experiments is to understand the mechanisms underlying the formation of heavy nuclei, with a mass greater than that of iron, in large stars. Scientists at the Frascati national laboratory are involved in ongoing research into nuclear force in the presence of “strange” quarks, which is important for understanding the behaviour of neutron stars.