Comet C/2020 F3 (NEOWISE). Panel a is an image obtained from Damian Peach⁶, reprinted with the author’s written permission. Panel b is the simulated image. This synthetic image is rotated by 66° westward with respect to the conventional north-up, east-to-left orientation to approximately match the orientation of the image in panel a. Red dots indicate the position of the first and second dark intervals between shells along the tail axis in both the observation and the simulation.