Lava tubes large enough to house cities could be structurally stable on the moon, according to a theoretical study presented at the Lunar and Planetary Science Conference on Tuesday.
The volcanic features are an important target for future human space exploration because they could provide shelter from cosmic radiation, meteorite impacts and temperature extremes..."We found that if lunar lava tubes existed with a strong arched shape like those on Earth, they would be stable at sizes up to 5,000 meters, or several miles wide, on the moon," Blair said. "This wouldn't be possible on Earth, but gravity is much lower on the moon and lunar rock doesn't have to withstand the same weathering and erosion. In theory, huge lava tubes - big enough to easily house a city - could be structurally sound on the moon."
A very cool concept. I remember decades ago the thrill of exploring a not-officially-open-to-the-public lava tube in the desert outside Flagstaff - easily navigable thanks to the flat floor. At an extraterrestrial site you wouldn't need to build a potentially-fragile dome over each structure. If the lava tube porosity could be sealed, an atmosphere could be generated. Now it's a matter of finding some tubes out there. Ones that aren't already occupied...