UH Researchers Find First Evidence of Ice on the Moon

A team of researchers from the University of Hawai‘i at Mānoa School of Ocean and Earth Science and Technology found the first direct evidence of water ice on the Moonʻs surface.  

Before this research, there was no direct evidence of ice on the Moon.

“This was a really surprising finding,” said Shuai Li, who is the lead author on the study and a postdoctoral researcher at the Hawai‘i Institute of Geophysics and Planetology in SOEST.

Li and the team analyzed data that was collected by the Moon Mineralogy Mapper (M3) on India’s Chandrayaan-1 mission launched in 2008. They found that the M3 data was similar to pure water ice they measured in the laboratory.

“While I was interested to see what I could find in the M3 data from PSRs, I did not have any hope to see ice features when I started this project,” Li said. “I was astounded when I looked closer and found such meaningful spectral features in the measurements.”

Li said that the ice on the Moonʻs surface is very patchy, unlike the pure and abundant ice found on other planets like Mercury and Ceres. “The spectral features of our detected ice suggest that they were formed by slow condensation from a vapor phase either due to impact or water migration from space,” Li said.

Their findings were also supported by other datasets, like the data collected by the Lunar Orbiter Laser Altimeter, the Lyman-Alpha Mapping Project and the Diviner instrument onboard America’s Lunar Reconnaissance Orbiter mission.

“The patchy distribution and smaller abundance of ice on the Moon compared with other planetary bodies suggest that the delivery, formation, and retention processes of water ice on the Moon are very unique,” said Paul Lucey, a professor at HIGP and co-author on the study.

“Given that the Moon is our nearest planetary neighbor, understanding the processes which led to water ice on the Moon provides clues to understand the origin of water on Earth and throughout the solar system,” Li said. “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.”

Exposed water ice (green or blue dots) in lunar polar regions and temperature. Credit: Shuai Li. Photo Courtesy of the University of Hawaiʻi Mānoa.

Lead author Shuai Li. Li is a postdoctoral researcher at the Hawai‘i Institute of Geophysics and Planetology (HIGP) in SOEST. Photo Courtesy of the University of Hawaiʻi Mānoa.