Moon's water supply too scarce for large cities, scientists find

Scientists say the moon lacks sufficient water to sustain large human cities, challenging ambitions like Elon Musk's plan for a lunar settlement. A study published Monday in Frontiers in Space Technologies estimates available water would support a million-person city for under two-and-a-half years without recycling. Using a generous estimate of 1 billion tons of water trapped in lunar glass beads, researchers calculated that efficient recycling at 98 percent, like the International Space Station, could extend that to 100 years. A smaller city of 100,000 people could last 1,000 years, while a town of 10,000 might survive 10,000 years. Experts suggest small research outposts, similar to Antarctic winter populations, are realistic in coming decades, with water potentially imported from asteroids or Saturn's moons long-term. They emphasize protecting scientifically valuable lunar ice and establishing international regulations to prevent a "gold rush" that could deplete the resource.