In November 2018 the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope pinpointed a fast radio burst, named FRB 181112. Follow-up observations with ESO’s Very Large Telescope (VLT) and other telescopes revealed that the radio pulses have passed through the halo of a massive galaxy on their way toward Earth. This finding allowed astronomers to analyse the radio signal for clues about the nature of the halo gas.
