The Pits

One of the most serious problems with establishing a moonbase is the atmosphere -- or more specifically, the lack of one. With no atmosphere to protect the surface from the hard radiation of the sun and meteorites moving faster than bullets, the only practical way to shield habitats on a large scale is by putting them beneath the surface. But if you've ever tried to dig a hole more than a couple of feet deep, you know what a pain that can be. Now multiply the size of the hole by several orders of magnitude and dig it while working in a spacesuit. Not fun, and definitely not very practical. So screw the shovel and use a tracked excavator, right? Not gonna happen. Using currently available technology, boosting several hundred tons of earth moving equipment out of Earth's gravity well and then soft-landing it on the lunar surface would be so expensive it would render the entire project financially impossible.

Fortunately, NASA may have found a solution: moon pits, formed by the collapsing roofs of lunar caves.

"Pits would be useful in a support role for human activity on the lunar surface," said Robert Wagner of Arizona State University, Tempe, Arizona. "A habitat placed in a pit -- ideally several dozen meters back under an overhang -- would provide a very safe location for astronauts: no radiation, no micrometeorites, possibly very little dust, and no wild day-night temperature swings."

Of course you see the ironic symmetry: we fly to the moon and become cavemen. Let's just hope we don't find any noisy black obelisks.

Source