Analysis the key elements of Martian habitable environment and its implication for Tianwen-3 site selection

The study of Martian habitable environment is a important aspect of Mars exploraion and plantary science. By summarizing Martian exploration missions and the research achievements, this paper analyzes four key points of Martian habitable environment, including key elements for life (carbon, nitrogen, sulfur and phosphorus), liquid water, climate conditions, and energy sources. Based on these factors, engineering safety, and scientific value, proposing that Utopia Planitia can be the preferred landing region for the Tianwen-3 mission, and further exploring the geological history and habitable environment characteristics of the Utopia Planitia. The results show that Utopia Planitia is an important candidate landing area with both scientific value and safety due to its geologic diversity, liquid water environment, and abundance of life-indicating minerals. This paper provides a reference for the Tianwen-3 mission , which will help the research of life exploration on Mars.