When the Aug. 21 solar eclipse unveils the sun’s normally dim atmosphere, the corona will look like an intricate, orderly network of loops, fans and streamers. These features trace the corona’s magnetic field, which guides coronal plasma to take on the shape of tubes and sheets.
These wispy coronal structures arise from the magnetic field on the sun’s visible surface, or its photosphere. Unlike the corona, the photosphere’s magnetism is a complete mess.