Reconstruction of a Solar Orbiter encounter with the ion gas tail from fragmented comet C/2019 Y4 (ATLAS)

Reconstruction of a Solar Orbiter encounter with the ion gas tail from fragmented comet C/2019 Y4 (ATLAS). In the diagram, lines identify interplanetary magnetic field lines in the solar wind; these are draped around the comet and form the typical magneto-tail with opposing orientation at the two sides. Solar Orbiter data from the Imperial College MAG magnetometer are shown along the spacecraft trajectory through the structure: arrows indicate the direction of the magnetic field, and length its intensity. The identified sharp boundary between the tail and the ambient solar wind on the draped side is indicated by the magenta dashed line.