In a first, scientists have detected surface exposed water ice on Moon’s permanently shaded regions (PSRs). The discovery was made by a team of scientists led by researchers from the University of Hawai’i at Mānoa School of Ocean and Earth Science and Technology (SOEST).
Scientists reveal that the distribution of ice on the lunar surface is very patchy – a feature that is quite different from what has been observed in other planetary bodies such as Mercury and Ceres. Findings indicate that the ice patches were formed by slow condensation from a vapor phase either due to impact or water migration from space. For the study researchers analyzed data acquired by the Moon Mineralogy Mapper (M3) onboard India’s Chandrayaan-1 mission launched in 2008. They found absorption features in the M3 data that were similar to those of pure water ice measured in the laboratory.
The study findings were validated with other datasets such as the data acquired by the Lunar Orbiter Laser Altimeter (LOLA), The Lyman-Alpha Mapping Project (LAMP), and the Diviner instrument onboard America’s Lunar Reconnaissance Orbiter (LRO) mission.
Before this research, there was no direct evidence of water ice on the lunar surface. Usually, M3 measures reflected light from the illuminated regions on the Moon. At PSRs, there is no direct sunlight reflected so M3 can only measure scattered light in those areas. Without an atmosphere, light bouncing around the surface of the Moon is scattered very weakly, producing a weak signal for the research team to work with.
Scientists say that they were surprised with the findings. The study reveals that the delivery, formation, and retention processes of water ice on the Moon are very unique. The understanding garnered through this study provides clues to understand the origin of water on Earth and throughout the solar system.
“A future Moon mission is needed to examine the whole lunar PSRs to map out all water ices and understand the processes which led to water on the Moon. This work provides a roadmap for future exploration of the Moon, particularly the potential of water ice as a resource”, said one of the researchers.