(a) The projected separation of Callisto from Jupiter at the time of each JWST observation from the perspective of the telescope. The subobserver longitude of Callisto is shown for each date. (b) The position of Callisto relative to the corotating Jovian plasma sheet (dashed line) at the time of each observation, in the reference frame of the plasma sheet. The arrows are scaled for both direction and relative distance. The labeled dates are accompanied by the distance of Callisto from the middle of the sheet in Jupiter radii, R_J = 71,492 km (B. A. Archinal et al. 2018). With the exception of the physical size of Callisto, the drawing is to scale. In this visualization, the direction of sheet motion is counterclockwise.