Shock-induced magnetic reconnection in the Venusian magnetotail.

Magnetic reconnection, a universal process governing energy release in astrophysical plasmas, has long been studied as a key phenomenon in magnetized planets. However, its drivers and impacts in unmagnetized bodies remain poorly understood. Despite the detection of magnetic reconnection in the near Venusian magnetotail over a decade ago, the physical mechanism enabling this process in a non-intrinsic magnetic field environment has remained unresolved. Here, we present a global magnetohydrodynamic simulation of Venusian magnetotail reconnection, providing a plausible explanation for this phenomenon. We demonstrate that reconnection is triggered by the compression of the draped interplanetary magnetic field following an interplanetary shock, a mechanism previously associated with terrestrial dynamics. Our results reproduce characteristic reconnection signatures at approximately 1.72 Venus radii down the tail and delineate the formation of three-dimensional magnetic structures consistent with reconnection topologies. These findings highlight a physically plausible pathway by which dynamic pressure enhancement associated with an interplanetary shock may trigger magnetotail reconnection in unmagnetized plasma environments. While based on a single case, these results may provide a physical basis for understanding potential drivers of atmospheric evolution on rocky planets and exoplanets.