Study Suggests Moon Cities Unfeasible Due to Limited Water Resources

Following Elon Musk's announcement in February that SpaceX would shift focus from Mars to building a city on the Moon, the researchers sought to determine how viable such a settlement could be. Martin Elvis, a senior astrophysicist at the Harvard and Smithsonian Center for Astrophysics and lead author of the study, explained that if one were to start with an estimated 1 billion tons of water, a population of 1 million people would consume the water within two and a half years. In comparison, with efficient recycling methods similar to those used on the International Space Station, this population could last up to 100 years; however, this scenario relies on extremely responsible water usage, which the researchers deemed unlikely.

The study highlights that a smaller city of about 100,000 people could sustain itself for approximately 1,000 years, while a town of 10,000 might have enough water for around 10,000 years. This suggests that long-term survival for smaller settlements might be feasible, prompting considerations for importing water from other celestial bodies in the solar system, such as the asteroid belt.

Ian Crawford, a professor of planetary science at Birkbeck, University of London, commented on the importance of the study for grounding expectations about lunar colonization. He emphasized the necessity of importing water or hydrogen from lunar materials if large settlements are to be established.

While a hypothetical “Moon Village” of about 1,000 people could potentially use lunar water without significant restrictions, researchers noted the importance of understanding the scientific value of lunar water ice before extensive harvesting. Simeon Barber, a senior research fellow at the UK’s Open University, pointed out that the lunar water could reveal insights about the environment that has persisted since the Moon's formation.

The study also underscored the high water demand of agriculture, estimating that feeding one person for a day would require between 2,000 to 5,000 liters of water. Suggestions for reducing water usage included adopting a more plant-based diet, given the significantly higher water demands of animal farming.

Researchers conveyed that despite potential water reserves, uncertainties about both the actual quantity and the extraction processes remain. They noted that areas containing water may be challenging to access due to extreme cold and potential contamination by chemicals. The eight largest craters on the Moon are believed to hold approximately 34 million tons of water, thereby raising concerns about resource management and the need for international regulations to prevent a rush for lunar exploitation.