Review of detection methods for water ice at lunar south pole

Abstract

[Objective] The permanently shadowed regions(PSRs) at the lunar south pole, due to their low temperatures and prolonged absence of sunlight, have become key reservoirs for lunar water ice. Clarifying the distribution, abundance, and form of occurrence of water ice in this region is a core scientific question for understanding the origin and evolution of lunar water sources. It is also a critical prerequisite for enabling in-situ resource utilization and sustainable deep space exploration on the Moon. [Methods] Existing research method include orbital remote sensing technologies and indirect analytical techniques. In terms of orbital remote sensing, neutron and gamma-ray spectroscopy, near-infrared and thermal infrared spectroscopy, and radar polarimetric imaging techniques are applied to analyze their principles and detection capabilities. For indirect analysis, methods such as impact plume analysis, thermal environment modeling, and micro-cold trap analysis are employed to evaluate the stability of water ice. [Results] In-situ drilling and thermal gas release analysis have been established as the final verification techniques for the presence of water ice. Through data analysis from missions such as Lunar Prospector, Chandrayaan-1, Lunar Reconnaissance Orbiter, and LCROSS, the accuracy, applicable scenarios, and limitations of different detection method are evaluated, revealing differences in their performance in detecting the distribution of water ice. [Conclusion] The future directions of technological development include breakthroughs in high-spatial-resolution remote sensing technologies to improve the accuracy of water ice distribution mapping; the development of lunar surface mobile robots equipped with autonomous navigation and precise sampling capabilities to support in-situ exploration in complex terrains; and the establishment of an “orbital-in-situ-simulation” multi-scale data fusion framework. This will form a comprehensive understanding of lunar water ice from macroscopic distribution to microscopic mechanisms, thereby providing technical support for lunar base construction and deep space exploration.

Keywords

lunar south pole / water ice / permanently shadowed regions / orbital detection / in-situ resource utilization