Scientists are using cutting-edge techniques to track water ice on the Moon—an essential resource for future space missions.
A University of Hawai‘i team utilized ShadowCam to peer into the Moon’s perpetually dark craters, refining estimates of surface ice. Another team introduced a cosmic ray-based method to detect deeply buried ice, a breakthrough in lunar exploration. Both approaches could revolutionize how we locate usable water beyond Earth, with Hawai‘i emerging as a key player in the growing space frontier.
Unlocking Lunar Water: Why Ice on the Moon Matters
Scientists and space researchers are working to identify where water ice exists on the Moon, and how much of it is there. Water ice is a crucial resource for future lunar missions. It could help support human life and be split into hydrogen and oxygen to make rocket fuel. To advance this effort, researchers at the University of Hawai‘i at Mānoa are testing two cutting-edge methods to detect ice on the Moon.
ShadowCam: Peering Into the Moon’s Darkest Corners
Previous research by Shuai Li, a scientist at the Hawai‘i Institute of Geophysics and Planetology (HIGP) in UH Mānoa’s School of Ocean and Earth Science and Technology (SOEST), found evidence of water ice in areas of the Moon that are permanently shadowed, specifically near its north and south poles. Building on that work, a new study led by graduate student Jordan Ando, who works in Li’s lab, analyzed images taken with a specialized instrument called ShadowCam. This camera is part of the Korea Lunar Pathfinder Orbiter, launched by the Korea Aerospace Research Institute.
Because the Moon’s polar craters never receive direct sunlight, some regions remain in permanent shadow. However, light can bounce from the illuminated walls of a crater and faintly light up the opposite side. ShadowCam was designed to detect these dimly lit areas, making it exceptionally well-suited to study the Moon’s darkest regions.
“Ice is generally brighter, that is, it reflects more light, than rocks,” said Ando. “We analyzed high-quality images from this sensitive camera to look really closely into these permanently shaded areas and investigate whether water ice in these regions leads to widespread brightening of the surface.”
While the ice in the shaded regions did not significantly brighten the surface, the team’s analysis of the ShadowCam images helps to refine the estimate of the amount of ice that could be on the lunar surface. Li’s previous method suggested that the lunar surface contains between five and 30 percent water ice. The analysis of Shadow Cam images narrows the range—indicating that water ice makes up less than 20 percent of the lunar surface.
Cosmic Rays: A New Tool for Lunar Ice Detection
In addition to these investigations of lunar ice at the surface, another group of UH Mānoa researchers with HIGP and the Department of Physics and Astronomy recently published a study in Geophysical Research Letters that outlines an innovative approach to detect buried ice deposits at the Moon’s poles.
“With our recent study, we showed that a new technique for detecting buried water ice on the Moon is possible using naturally-occurring cosmic rays,” said Emily S. Costello, study lead author and postdoctoral researcher at HIGP. “These ultra-high-energy cosmic rays strike the lunar surface and penetrate to the layers below. The rays emit radar waves that bounce off buried ice and rock layers, which we can use to infer what’s below the surface.”
Subsurface Secrets Unveiled With High-Energy Physics
The team used an advanced computer simulation that tests how radar waves travel through the lunar soil and how they encode information about possible buried ice layers.
“This method for searching for water ice on the Moon is brand new and really exciting,” said Christian Tai Udovicic, a co-author on the study who presented the findings at the recent Lunar and Planetary Science Conference in Houston, Texas. “Since it relies on high-energy physics that only a few scientists in the world are experts in, even planetary scientists who are studying ways to find lunar water ice are often surprised when they hear about this technique.”
A team of HIGP and Physics Department researchers are working to assemble a radar instrument specifically tuned to listen for these signals on the Moon and hopes to test the full system by early 2026. They will look for opportunities to send it to the Moon to hopefully detect large deposits of buried water ice on the Moon for the first time.
Hawai‘i’s Role in Future Moon Missions
“More and more, Hawai‘i is becoming a hub for space exploration, and specifically the exploration of the Moon,” said Costello. “These projects, led by UH Mānoa scientists, represent up-and-coming opportunities for students and professionals in Hawai‘i to lead and participate in the budding space industry.”
References:
“Radiance Contrasts at Possible Lunar Water Ice Exposures Seen by ShadowCam” by Jordan Ando, Shuai Li, Mark Robinson and Robert Wagner, 19 March 2025, The Planetary Science Journal.
DOI: 10.3847/PSJ/adb8d1
“Cosmic Rays and the Askaryan Effect Reveal Subsurface Structure and Buried Ice on the Moon” by E. S. Costello, R. R. Ghent, A. Romero-Wolf, P. W. Gorham, P. G. Lucey, C. J. Tai Udovicic, P. Linton, A. Ludwig, K. McBride, C. Miki, E. Oberla, J. Rolla and A. Jung, 26 March 2025, Geophysical Research Letters.
DOI: 10.1029/2024GL113304
Never miss a breakthrough: Join the SciTechDaily newsletter.
Follow us on Google and Google News.