Joint Observation of a Rotational Discontinuity by Tianwen‐1 and MAVEN at Mars

Abstract The solar wind plays a crucial role in the evolution of planets in the solar system, particularly Mars. Mars has no global intrinsic magnetic field, leading the solar wind to interact directly with the Martian ionosphere and atmosphere. However, there are many strong‐current magnetic structures in the solar wind, which can directly affect the Martian induced magnetosphere and plasma environment. Using Tianwen‐1 and MAVEN data, we present the first joint observation of a rotational discontinuity (RD) at Mars. The thickness of the RD is about 9 ion inertial lengths, and the tangential current density at the RD's center reaches ∼12 nA/m 2 . Based on the two‐spacecraft joint analyses, we find that the RD may be a curved structure. These results can improve our understanding of Martian space environment.