Astronomers using @ESA_XMM have probed the gas-filled haloes around #galaxies in a quest to find ‘missing’ matter thought to reside there, but have come up empty-handed – so where is it? 🔎 Full story: https://t.co/nbtd8AuCA5 pic.twitter.com/0d3YBboZrf

— ESA Science (@esascience) April 18, 2018