Years of Mars emplacement exploration and meteorite analysis have found that chlorine oxides (ClOx -) are common on the surface of Mars. Perchlorate (ClO4 -; CL is + 7 valence) and chlorate (clo5 -; CL is + 5 valence) are two stable forms of chlorine oxides. Chlorine oxide can keep water liquid at - 70 ° C, participate in the redox process on the surface of Mars, and can also be used as an energy source for some microorganisms. Clarifying the main forms, distribution characteristics and environmental effects of oxychloride on Mars is of great significance for the chlorine cycle at the Martian soil atmosphere interface, the exploration of Martian organic matter, the hazard assessment of manned fire exploration in the future and the utilization of in place resources.

Zhao Yuyu's team from the lunar and Planetary Science Research Center of the Institute of geochemistry, Chinese Academy of Sciences, together with scholars in the fields of physical chemistry and Planetary Science at home and abroad, has carried out a series of studies on the formation of chlorine oxides on Mars and their environmental effects, and made important progress.

Using the Mars surface process simulation experimental platform owned by the lunar and Planetary Science Research Center, the scientific research team carried out experimental research on the controlling factors of ClO4 - and ClO3 - generation ratio. The results show that the physical state (i.e. solid, liquid or gas) of chloride ion (Cl -) and the characteristics of its coexisting minerals (such as semiconductor, specific surface area and acidity) are the main factors controlling the formation ratio of ClO4 - / ClO3 -, while the type of oxidant (UV irradiation or ozone) and atmospheric composition (Earth's atmosphere or Martian atmosphere) are only secondary factors. The widespread distribution of Cl - and O4 - on the surface of Mars highlights the importance of the arid climate of Mars since the C1 - and O4 - levels on the surface of Mars. On February 8, relevant achievements were published in nature astronomy.

With the help of ultra-low temperature phase diagram and Martian global climate simulation, the research team conducted in-depth research on the genetic mechanism of high content of perchlorate (ClO4 -) and high ClO4 - / Cl - ratio detected in Martian arctic soil. The results show that under the synergistic effect of low-temperature arid environment and aeolian sand material exchange in the Martian arctic, the chloride salt in the soil will form brine with specific high ClO4 - / Cl - ratio through low-temperature water vapor deliquescence or ice eutectic, resulting in the continuous production and preservation of chloride salt with the characteristics of high ClO4 - / Cl - ratio in the Martian arctic topsoil. This discovery demonstrates the unique control of the Martian arctic environment over the global chlorine cycle. High ClO4 - / Cl - ratio is not a universal feature of Mars, but can be used as an important chemical index to trace deliquescence in the frozen and arid environment of Mars. On February 4, relevant achievements were published in communications earth & environment.

The research work has been supported by the special strategic leading science and Technology (class B) planetary science of the Chinese Academy of Sciences, the National Natural Science Foundation of China, the pre research project of civil aerospace technology, the key deployment project of the Institute of Geology and Geophysics of the Chinese Academy of Sciences, the talent training plan of the "light of the west" of the Chinese Academy of Sciences, the special support project for the development of national major scientific instruments and equipment, the upgrading and transformation project of scientific instruments in Shandong Province Supported by the international partnership program of the Chinese Academy of Sciences, the youth innovation promotion association of the Chinese Academy of Sciences, and the key research program of Frontier Science of the Chinese Academy of Sciences.