Overview
- The peer‑reviewed paper published Monday finds that a one‑billion‑tonne estimate of polar ice would support a one‑million‑person lunar city for only about 100 years if water is recycled at the International Space Station’s 98 percent efficiency.
- Authors note that current best estimates are roughly 30 times smaller than one billion tonnes, which would shorten those lifetimes by the same factor and make large settlements effectively unsustainable.
- Smaller settlements of roughly 1,000 to 10,000 people can be sustained for centuries on the ice already mapped in permanently shadowed polar craters.
- Power is not the limiting factor because kilometer‑tall photovoltaic towers on crater rims could produce about three gigawatts of electricity, enabling local industry without immediate reliance on nuclear plants.
- The researchers call for deeper subsurface prospecting, far higher recycling, low‑water farming, imports from water‑rich asteroids, and international resource governance because planned robotic and crewed missions in 2027–2028 could materially change what water is known to be accessible.