Plasmas are omnipresent in the cosmos, whether it is the space surrounding the Earth and the Sun, the stars or the ionized gas in which they bathe (the interstellar medium). Beyond 50 km of altitude, the Earth’s atmosphere is transformed into a plasma, which is called the ionosphere. Indeed, the few molecules present are immediately dissociated and ionized by the radiation of the stars that reaches them without filter. As this plasma evolves in the magnetic field of the Earth, the movement of charged particles generates electromagnetic waves with which the plasma couples in a non-linear way. Moreover, complex phenomena such as magnetic instabilities develop and are the subject of our studies. Finally, thanks to large lasers such as the Laser Megajoule (LMJ) of the CEA, a new research approach called “laboratory astrophysics” has emerged. It consists in reproducing in the laboratory plasmas representative of those found in the universe. This work allows to progress in the understanding of various astrophysical phenomena which remained inaccessible until now.