SDA reflect conditions whereby particular magnetic topologies connect the nightside atmosphere to a source of abundant electrons, whether dayside photoelectrons or sufficiently energetic magnetotail/sheath electrons. In particular, midnight sinuous discrete aurora appear to be a projection of the tail current sheet, a persistent but highly variable feature of Mars’ double-lobed magnetotail resulting from the draping of the IMF around the conducting obstacle of Mars’ dayside ionosphere. This interpretation is supported by magnetohydrodynamic (MHD) simulations, showing that the orientation of the tail current sheet approximately matches the orientation of midnight SDA.