Recently, the team of young scientists from the State Key Laboratory of Precision Geodesy, Innovation Academy for Precision Measurement Science and Technology (APM), Chinese Academy of Sciences, led by professor SUN Daoyuan and professor MAO Zhu from the University of Science and Technology of China, in collaboration with international scholars, has made significant progress in the field of planetary science research. The research team, through in-depth analysis of the marsquake data recorded by NASA's InSight lander, has for the first time confirmed the existence of a solid inner core with a radius of approximately 600 kilometers inside Mars and revealed that its main composition might be crystalline iron-nickel alloy rich in light elements. At Beijing time on September 3rd, this achievement was published in the journal Nature and selected as a press release for Nature.

Schematic diagram of the deep-structure of Mars

The off-white (or light gray) areas represent the solid inner core detected and discovered using InSight mission data in this study

This study has, for the first time, confirmed the existence of a solid inner core in planets other than Earth and verified that Mars has a core-mantle differentiation structure similar to that of Earth. The seismological methods for Mars, innovatively developed by the research team, provide an important reference for using seismological methods to probe the deep-structure of celestial bodies like the Moon in future lunar exploration and other missions. Meanwhile, this achievement marks a crucial step taken by the Chinese research team in the field of planetary interior structure exploration, and demonstrates China's innovative capability and international influence in the interdisciplinary research of planetary science and geophysics.

The reviewers of the journal Nature spoke highly of this work, pointing out: " The authors have done a detailed job of using multiple working lines of evidence for their phase detection analysis. Martian seismology is notably tough，so congratulations to the authors for doing such a thorough and careful job!" And it is commented that, " To me，this is a really interesting paper and I think that it will generate discussion for years to come！"

Dr. BI Huixing from the University of Science and Technology of China (USTC) is the first author of this paper. Professor SUN Daoyuan from USTC serves as the corresponding author. Professor MAO Zhu from USTC, special-term associate research fellow SUN Ningyu from USTC, Dr. DAI Mingwei, as well as DOUGLAS Hemingway from the University of Texas at Austin, are the co-authors of this paper. The State Key Laboratory of Precision Geodesy is one of the accomplishing institutions.

Link to the article: https://www.nature.com/articles/s41586-025-09361-9