The moon's surface is home to a surprising number of "lunar pits" — and those pits may one day be home to astronauts.
NASA released a statement Thursday that the moon has as many as 200 lunar pits, and it hopes those pits will be able to shelter astronauts.
Since the pits aren't formed by asteroid or meteor impact, they're not technically craters, Vice explains. The pits are likely formed from parts of the moon collapsing over caves, widening underground to form larger, underground caves. The original caves, NASA says, were likely formed by ancient lava streams hollowing out the moon's underground channels.
"Pits would be useful in a support role for human activity on the lunar surface," Robert Wagner, an Arizona State University researcher and one of the scientists who discovered the moon's holes, said in a statement. "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."
The pits, discovered by NASA's Lunar Reconnaissance Orbiter, range in diameter from five meters to more than 900 meters. According to Wagner, the next step is to lower probes into the pits, since pits "cannot be explored very well from orbit." Once scientists have a better sense of what's inside the pits, they can take the next step toward setting up underground lunar bases.
Check out more about the lunar pits in NASA's video below. --Meghan DeMaria