NASA Selects Team to Probe Lunar Cave That Could Shelter Future Astronauts

NASA has picked a team to send instruments to the moon to answer a question that has been building for years: Is there actually a cave down there?

The Planetary Science Institute, a nonprofit research organization, won the contract to lead what they're calling GIMLI—the Geophysical Instruments for Marius Lunar pit Investigation. The target is a large pit in the Marius Hills region of the moon, a place with a long history of volcanic activity. From orbit, scientists have spotted what look like openings to underground spaces, and they want to know if those openings lead somewhere substantial. If they do, those caves could one day shelter astronauts from the moon's brutal surface conditions: radiation that would kill an unprotected human in days, and temperature swings that swing from 250 degrees Fahrenheit in sunlight to minus 280 in shadow.

Than Putzig, an associate director at PSI, is leading the effort. He's bringing back a technique that hasn't been used on the moon since the Apollo astronauts left in the early 1970s—active-source seismic surveying, the kind of thing where you create small vibrations and listen to how the ground responds. GIMLI will combine that with ground-penetrating radar and gravity measurements, essentially using three different ways of looking underground at once. Honeybee Robotics, owned by Blue Origin, is building most of the equipment. The instruments will ride to the moon on a commercial lander and rover, part of NASA's effort to use private companies for lunar cargo.

The Marius Hills pit is not small. It's a hole in one of the moon's most geologically interesting regions, and it may be an entrance to a lava tube—a tunnel formed by flowing lava millions of years ago. On Earth, lava tubes are common features of volcanic landscapes. If they exist on the moon in substantial form, they could tell scientists how the moon's volcanism actually worked, and they could offer something more immediate: ready-made shelter for future human missions.

The instruments themselves are straightforward in concept. Cameras will photograph the pit and its walls. Seismic sensors will detect vibrations sent through the ground. A gravimeter will measure subtle changes in gravity that might indicate a void below the surface. Ground-penetrating radar will send signals into the subsurface and listen for echoes. Together, these tools should be able to detect whether a cave exists beneath the pit, and if one does, help determine how big it is.

Even if GIMLI finds nothing—no cave, no lava tube—the mission will still produce useful science. The measurements of the subsurface around the pit could help explain how the pit formed in the first place. The walls of the pit expose layers of rock and regolith that are normally buried, a geological record written in stone. Studying those layers could reveal how lava moved across the moon's surface and whether eruptions were separated by long periods of quiet or happened in rapid succession.

The team includes researchers from Boise State University, Johns Hopkins University, the Lunar and Planetary Institute, and the University of Oslo. The Norwegian Space Agency is providing the ground-penetrating radar equipment. This is not a small American effort; it's a collaboration that reflects how lunar science has become genuinely international.

Gareth Morgan, a senior scientist at PSI and deputy principal investigator on the project, framed what confirmation of a substantial lava tube would mean: it would give scientists a way to use what they know about caves on Earth to understand how the moon actually worked. A confirmed lava tube would be more than a geological curiosity. It would be proof that the moon has natural structures capable of protecting human beings from an environment that, without shelter, is lethal. That changes how you think about living there.