BY MARIA BURKE
NASA’s Artemis Project has set the goal of establishing a permanent crewed base on the Moon by the end of the decade. But one of the most significant obstacles to humans surviving on the Moon is the availability of clean water. Astronauts will need a reliable supply for drinking and growing food.
‘5.6% of the soil – known as ‘regolith’ – around the Moon’s south pole is estimated to be water frozen as ice,’ says Meganne Christian, Reserve Astronaut at the UK Space Agency (UKSA). ‘If it can be successfully extracted, separated from the soil and purified, it makes a crewed base viable.’
A small Gloucestershire, UK-based company called Naicker Scientific has developed a technology that uses microwaves to defrost lunar ice, then ultrasound to break down contaminants. Its SonoChem System, which won the UKSA’s Aqualunar challenge, produces powerful sound waves which spontaneously form millions of tiny bubbles in contaminated water. The extreme temperatures and pressures inside these microbubbles mean that when they expand and collapse, highly reactive free radicals are created. The free radicals decompose contaminants.
‘Imagine digging up the soil in your back garden in the middle of winter and trying to extract frozen water to drink,’ says Lolan Naicker of Naicker Scientific. ‘Now imagine doing it in an environment that is -200°C, a nearly perfect vacuum, under low gravity, and with very little electrical power. That’s what we will have to overcome on the Moon. If we can make the SonoChem System work there, we can make it work anywhere, whether that’s on Mars’ glaciers, or here on Earth in regions where accessing clean water is still a challenge.’
Another challenge is finding sufficient ice. In February 2025, a thermal imaging camera built by researchers at the University of Oxford blasted off to the Moon as part of NASA’s Lunar Trailblazer mission, which aims to map water sources and shed light on the lunar water cycle.
In orbit, the spacecraft’s instruments will map the surface temperature and mineral composition of the lunar surface 12 times/day. They will examine features including the permanently shadowed craters at the Moon’s South Pole, which could contain significant quantities (potentially 600m t) of ice.
‘The measurements of temperature will help confirm the presence of the water signal … [and together] the instruments will map the composition of the Moon, showing us details that have only been hinted at previously,’ says Neil Bowles of the University of Oxford, UK.
The origin of lunar water is still unclear. Possible reasons include comets and ‘wet asteroids’ crashing into the Moon, or ancient volcanic eruptions disgorging water vapour from the Moon’s interior. One prevalent theory is that most lunar water was produced in situ via solar wind interactions with lunar silicates.
A team led by Vrije Universiteit, Brussels (VUB), in Belgium, may have moved one step closer to finding out. In December 2024, they reported that the isotopic signatures of lunar water revealed a dual heritage: one part originating from early Earth-like material and another delivered through comets.
The team analysed water in nine samples from the Apollo lunar missions, using a high-precision triple oxygen isotope technique. This method separates water into its various binding phases – loosely bound, tightly bound, and trapped within minerals – via stepwise heating at different temperatures.
The study has three key results: the oxygen isotopic composition closely matches enstatite chondrites, a meteorite type believed to be Earth’s building blocks; and a significant portion of lunar water shows isotopic similarities to comets. It also challenges the prevalent theory that water was made in situ, presenting instead a complex mixing of sources (PNAS, 2024, DOI: 10.1073/pnas.2321069121).
‘Our data suggest that the Moon inherited water tracing back to Earth’s formation, followed by later contributions from comets, delivering the water reservoirs we see today,’ says Maxwell Thiemens of the VUB. ‘The data not only enhance our understanding of the Moon’s past but also paves the way for future space exploration and resource utilisation. These findings should redefine how we think about water as a resource for long-term lunar habitation.’
Meanwhile, a new study by Durga Prasad’s team at the Physical Research Laboratory in Ahmedabad, India, suggests that areas on the Moon where ice can form may be more numerous and easier to access than previously thought.
The study analysed temperature readings taken at the lunar surface and to a depth of 10 centimetres taken in 2023 by the Chandrayaan-3 mission.
The only other previous direct measurements were taken in the 1970s by the Apollo missions. However, these missions landed near the equator, several thousand kilometres from proposed landing sites for future manned missions.
The team derived a model of how slope angle affects surface temperature. It indicated that, for slopes facing away from the Sun and towards the nearest pole, a slope with a greater than 14° angle may be cool enough for ice to accumulate close to the surface.
This is similar to conditions at the lunar poles, including those at the proposed landing sites for NASA’s manned Artemis missions near the lunar south pole (Commun Earth Environ, 2025, 6, 153).
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