M87 jet in polarized light, Atacama Large Millimeter/submillimeter Array (ALMA) image. M87 is an elliptical galaxy, 50 million light years away from Earth. It has a supermassive black hole at its core which gathers infalling material and produces powerful jets that launch energetic particles outwards. The jets contains clumps or knots (bright areas) that form when material falls on them.The lines on the image mark the orientation of polarisation of magnetic fields. This allows researchers to understand what the structure of the magnetic field along the jet looks like.