Magnetic Field Structures in the Near-terminator Induced Magnetospheres of Venus and Mars

Venus and Mars, our two neighboring planets, have no global intrinsic magnetic fields, and the induced magnetospheres are formed in their solar wind interactions through mass loading of magnetic flux tubes carried by the solar wind and draping around the highly conducting ionosphere. Although they have similar global magnetic environments in their induced magnetosphere controlled by the interplanetary magnetic field and the solar wind motional electric field, their differences in planetary size, solar wind conditions, crustal magnetic fields, etc. also have measurable impacts. We comparatively study the magnetic field structures in the Venusian and Martian induced magnetospheres near the terminator via observations. The nature of their current systems and the features of magnetic structures such as flux ropes are examined in the near-terminator space and the effects of solar activity, interplanetary magnetic field, and crustal fields are explored. The results reveal the solar wind interaction with unmagnetized planets near the terminator, and a simulation provides a three‐dimensional view.