A new view of the region closest to the supermassive black hole at the center of the galaxy has shown important details of the magnetic fields close to it—and hints about how powerful jets of material can originate in that region. A worldwide team of astronomers using the Event Horizon Telescope (EHT) measured a signature of magnetic fields—called polarization—around the black hole. Polarization is the orientation of the electric fields in light and radio waves, and it can indicate the presence and alignment of magnetic fields. The new images allowed scientists to map magnetic field lines near the edge of Messier 87’s (M87’s) black hole, and are a key to explaining how the black hole, 50 million light-years from Earth, can launch energetic jets from its core. The black hole at M87’s center is more than 6 billion times more massive than the Sun. Material drawn inward forms a rotating disk—called an accretion disk—closely orbiting the black hole. Most of the material in the disk falls into the black hole, but some surrounding particles escape and are ejected far out into space in jets moving at nearly the speed of light. “The newly published polarized images are key to understanding how the magnetic field allows the black hole to ‘eat’ matter and launch powerful jets,” said Andrew Chael, a NASA Hubble Fellow at the Princeton Center for Theoretical Science and the Princeton Gravity Initiative in the U.S.