Proper motion in μ_δ and μ_α cos δ as a function of projected distance from the SMC centre. Grey dots in the background indicate the distribution of the simulated particles (Diaz & Bekki 2012). Blue triangles show the median VMC proper motion, while the red squares show the median Gaia DR2 proper motion of stars across the Magellanic Bridge. Black diamonds indicate HST proper motion measurements (Zivick et al. 2019). Simulated proper motions (GalMod) of the Milky Way foreground stars are shown as black circles.