Astronomers have produced the first direct image of the Universe’s large-scale ‘cosmic web’, capturing a filament of hydrogen gas stretching roughly three million light-years between two distant active galaxies. The breakthrough resolves a structure that, until now, had been inferred only from simulations and indirect observations. The picture was obtained with the Multi-Unit Spectroscopic Explorer (MUSE) on the European Southern Observatory’s Very Large Telescope in Chile. After several hundred hours of exposure, the instrument detected the faint glow of hydrogen that forms a bridge of matter funnelling gas into the galaxies and fuelling star formation. Researchers led by Davide Tornotti of the University of Milano-Bicocca say the image provides “solid evidence” that existing cosmological models accurately describe how galaxies assemble and evolve. Fabrizio Arrigoni Battaia of the Max Planck Institute added that mapping additional filaments will refine estimates of how much normal matter is locked up in the web’s vast, previously unseen reservoirs.