The largest known black hole jets, 23 million light years across, have been discovered in the distant universe. This pair of particle beams launched by a supermassive black hole is over a hundred times larger than our galaxy, the Milky Way. The largest known black hole jets, 23 million light years across, have been discovered in the distant universe. This pair of particle beams launched by a supermassive black hole is over a hundred times larger than our galaxy, the Milky Way. Astronomy Phys.org – latest science and technology news stories