Galaxies exchange matter with their external environment thanks to galactic winds. The MUSE instrument from the Very Large Telescope has, for the very first time, mapped the galactic wind that drive these exchanges between galaxies and nebulae. This observation led to the detection of some of the Universe’s missing matter. Galaxies can receive and exchange matter with their external environment thanks to the galactic winds created by stellar explosions. Thanks to the MUSE instrument[1] from the Very Large Telescope at the ESO, an international research team, led on the French side by the CNRS and l’Université Claude Bernard Lyon,[1,2] has mapped a galactic wind for the first time. This unique observation, which is detailed in a study published in MNRAS on September 16, 2021, helped to reveal where some of the Universe’s missing matter is located and to observe the formation of a nebula around a galaxy. Galaxies are like islands of stars in the Universe, and possess ordinary or ba...