Occurrence and Infrared Absorption Spectra of Martian Water
After nearly half a century of exploration,the researches of Martian water have made im-portant achievements,which provides essential information for understanding the historical information of Martian water and the evolution of the Martian environment,especially arousing the enthusiasm of human beings to search for life on Mars.The study of the occurrence and host minerals of Martian wa-ter is of great significance for understanding the composition of Martian surface materials,the evolution of Martian environment and climate,and the livability of life.Infrared spectroscopy is an important method to identify the occurrence of water on the Martian surface and the host minerals.At present,wa-ter vapor,water ice and various aqueous substances such as sulfates,clay minerals,hydroxides and hy-drated silica have been identified on the Martian surface,indicating that there were several periods of aqueous activities in different water environments in Martian history.In this paper,the occurrence of Martian water and the information of Martian historical environment are summarized,and the infrared spectral characteristics of different water-bearing minerals and the main influencing factors including the type of host minerals,temperature,grain size and mixture are synthetic analyzed.Finally,the changes of infrared spectral absorption characteristics of groups such as H2O and OH are generalized.With the help of China's ongoing exploration of Tianwen-1 and future Tianwen-3 missions,breakthroughs can be made in understanding the origin and evolution of Martian water and the habitability of Mars.