Researchers from the University of Milan-Bicocca have captured the first high-definition images of the "cosmic web" that structures the Universe. Using MUSE (Multi-Unit Spectroscopic Explorer), an innovative spectrograph installed at the Very Large Telescope of the European Southern Observatory in Chile, the team captured a cosmic structure dating back to a very young Universe. The discovery, published in Nature Astronomy, opens a new perspective for understanding the nature of dark matter. Leveraging the instrument’s capabilities, the research group led by Michele Fumagalli and Matteo Fossati, professors in the astrophysics unit of the University of Milan-Bicocca, conducted one of the most ambitious observation campaigns ever carried out with MUSE in a single region of the sky, collecting data for hundreds of hours. "Dark matter forms an intricate cosmic web made up of filaments, at whose intersections the brightest galaxies emerge," explains Fumagalli. "This cosmic web is the framework upon which all visible structures in the Universe are created: within these filaments, gas flows to reach and fuel star formation in galaxies." Until now, observing the cosmic web has been impossible because the gas within the filaments emits only a faint glow. Thanks to its high sensitivity to light, MUSE has enabled scientists to capture detailed images of this cosmic structure. Led by PhD student Davide Tornotti and his team at the University of Milan-Bicocca, the study leveraged this ultra-sensitive data to produce the sharpest image ever captured of a cosmic filament—stretching 3 million light-years and connecting two galaxies, each home to a supermassive black hole.