Lunar water scarcity threatens large-scale Moon settlements

A new study published in ‘Frontiers in Space Technologies’ suggests that establishing large-scale human cities on the Moon faces a significant hurdle: limited water resources. Astrophysicists Martin Elvis and Jonathan McDowell analyzed the sustainability of lunar settlements based on available water ice found in permanently shadowed craters at the lunar poles.

While optimistic estimates once suggested up to one billion metric tons of water could exist, current estimates are significantly lower. The researchers found that a city of one million people would exhaust even the most generous reserves in just a few years without recycling. Even with a highly efficient 98% water recycling system, similar to those used on the International Space Station, a population of one million would only be sustainable for slightly over a century.

In contrast, energy production appears more viable. The study notes that solar power could be harvested effectively from crater rims that receive near-constant sunlight. While visionaries like Elon Musk and Jeff Bezos have proposed large-scale lunar developments, researchers suggest a more realistic near-term scenario involves smaller settlements, such as villages or towns of 10,000 people, which could utilize lunar water for hundreds or even thousands of years.