Using the eROSITA X-ray telescope onboard the Spectrum-Roentgen-Gamma (SRG) space observatory and CSIRO’s Australian Square Kilometre Array Pathfinder (ASKAP), astronomers have spotted a 49-million-light-year-long intercluster filament in the merging galaxy cluster system Abell 3391-Abell 3395, confirming current ‘Big Bang’ ideas about the origin and evolution of the Universe. Simulation showing the distribution of hot gas (left), compared with the eROSITA X-ray image (right) of the Abell 3391-Abell 3395 system. Image credit: Reiprich et al., doi: 10.1051/0004-6361/202039590. “More than half of the matter in our Universe has so far remained hidden from us,” said University of Bonn’s Professor Thomas Reiprich and colleagues.