PLANETARY MAGNETIC FIELDS AND MEASUREMENTS
Seminars
Summer Semester
Chief Scientist of the Strategic Priority Research Program (Category B) of the Chinese Academy of Sciences (CAS) "Formation, Evolution, and Habitability of Terrestrial Planets" and Field Scientist for the National Planetary Exploration Program. Professor Wang has significantly contributed to the field of space physics, particularly in understanding solar eruptions and their impact on Earth's and planetary space environments. He has also led the development of space magnetic field and particle detection technologies. Notably, his team developed the Tianwen-1 Mars Magnetometer, which achieved China's first precise measurement of the Martian space magnetic field. His accolades include the Chinese Geophysical Society Fu Chengyi Youth Science, China Youth Science and Technology Award, the inaugural Tan Kah Kee Young Scientist Award, Chinese Ministry of Education Natural Science Award (First Class), and the inaugural XPLORER Prize.
A planet is an open system. A planet’s magnetic field is one of its most important intrinsic properties, reflecting its internal characteristics and connecting it to the broader solar system by mediating matter and energy exchange. Measuring planetary magnetic fields is key to understanding their origin and evolution—such as the disappearance of intrinsic magnetism on Mars and Venus—and can help identify subsurface oceans, as with Jupiter’s moons, through analysis of periodic magnetic field variations. These measurements also shed light on ion escape and atmospheric evolution, for example, revealing how solar eruptions affect ion escape from Mars. Additionally, magnetic field data support space weather prediction, such as the relationship between auroras and magnetic field topology. Accurate magnetic field measurement is fundamental but faces different technical challenges depending on the target and region. High-precision measurements in weak magnetic environments, without magnetic cleanliness platforms, remain a major challenge. Tianwen-1’s Mars magnetometer achieved breakthroughs in this area via on-orbit calibration. Looking ahead, next-generation atomic magnetometers may be key for detecting even weaker fields at the edge of the solar system. Beyond in-situ measurements, remote sensing—such as Zeeman effect observations—offers a promising path from point to area measurements. Achieving remote imaging of planetary magnetic fields could drive significant advances in planetary science. This report reviews the development, scientific significance, measurement techniques, and future directions of planetary magnetic field research.