Scientists have found the perfect spot to set up camp on the moon

Our past visits to the moon have been short and fleeting. And while the Apollo astronauts spent 22 happy hours there, given that a moon-day last nearly a month, that’s nowhere near enough for an overnight visit. Still, there are various plans for humans to return to the moon – either as part of a wider Mars mission or just for the hell of it – and the question of where a moon base should be built is one that has been on scientists’ minds. A recent paper published in Geophysical Research Letters has a promising new suggestion: giant caverns in the moon’s surface created from when the astronomical body was volcanic.

The paper, written by scientists from NASA and JAXA, describes how dark crater-like features of the moon are actually likely entrances to giant caverns, formed millions of years ago from flowing lava that has long since dried up. These ancient caverns, located near the Marius Hill region of the moon, are described by the researchers as a “pristine environment to conduct scientific examination of the Moon’s composition and potentially serve as secure shelters for humans and instruments.”

“It’s important to know where and how big lunar lava tubes are if we’re ever going to construct a lunar base,” commented Junichi Haruyama, a senior researcher at JAXA. “But knowing these things is also important for basic science. We might get new types of rock samples, heat flow data and lunar quake observation data.”

While the moon’s elements are nowhere near as challenging as those that astronauts will face when they finally walk on Mars’ surface, it does present difficulties of its own: chiefly the fact that no atmosphere means no protection from the Sun’s dangerous rays. These naturally formed shelters would offer some protection with no building time required.

The idea that there are naturally occurring lava tubes on the moon isn’t a new one, but the paper offers pretty conclusive evidence that this is more than just a hunch. The scientists were able to analyse radar data from the SELENE spacecraft, firing bursts at the entrance to caverns and measuring the echo pattern. Specifically, they were looking for a decrease in echo power, followed by a larger peak which would demonstrate the presence of both a floor and a ceiling in the lava tube. And that’s what they found.

That’s good evidence, but it was all but confirmed by cross-checking the data to NASA’s GRAIL mission, where the space agency was looking for areas where mass was lower than expected. The lava tube matches areas of low mass: in other words, we’re looking at a huge cavern – easy enough for a moon base with plenty of headroom. The scientists estimate that it’s several kilometres long, and at least a kilometre tall and wide. Large enough to comfortably house Philadelphia.

That’s very good news indeed and makes the prospect of going back considerably more appealing. We may even stay the night this time.

Image: Adam Wyles, used under Creative Commons