A thread through the cosmos 🧵 Astronomers have discovered an enormous filament of hot gas stretching between four galaxy clusters – and it might help solve one of astronomy’s biggest mysteries. Over a third of the ‘normal’ matter in our local Universe is missing. Not dark matter or dark energy – but the everyday stuff that makes up stars, planets and us. So where is it? Thanks to our XMM-Newton and jaxajp Suzaku X-ray space telescopes, scientists have now found and carefully measured a 23-million-light-year-long filament in the Shapley Supercluster. It’s more than 10 times as massive as our galaxy and over 10 million degrees hot. And it could be hiding some of that elusive missing matter. By combining precise X-ray and optical data, researchers were able to isolate the filament from nearby galaxies and black holes for the first time – a huge leap forward in understanding the vast ‘cosmic web’ that connects the Universe. This is the first filament ever studied in such detail, and...