NASA Chooses GIMLI to Probe Marius Pit for Possible Lunar Cave Base
NASA selected a Planetary Science Institute-led proposal called GIMLI to study the Marius lunar pit and check whether a large cave extends beyond its opening. The effort, led by Than Putzig, involves the Norwegian Space Agency, Honeybee Robotics, and NASA's CLPS and PRISM programs. A confirmed subsurface cavern could provide future astronauts with a safer place to operate on the Moon.
NASA's Artemis program aims for sustained lunar exploration and development, not just brief visits. Lunar caves are being considered as potential habitat sites, alongside the South Pole-Aitken Basin. GIMLI — Geophysical Instruments for Marius Lunar pit Investigation — is led by the Planetary Science Institute, with Than Putzig as principal investigator.
The Marius Hill Pit sits in Oceanus Procellarum, a volcanically varied near-side region. Orbital observations have revealed sinuous rilles and skylights, suggesting collapsed lava tubes formed roughly 3.8 to 3 billion years ago. GIMLI's instruments — ground-penetrating radar, seismics, a gravimeter, and cameras — would measure any void's dimensions.
If a substantial cavern is confirmed beneath the Marius pit, it could reshape how space agencies plan long-term lunar operations, offering crews shielding from radiation, micrometeorites, and extreme temperature swings. That may lower some risks for astronauts and for the engineers designing surface infrastructure. The benefits would likely extend beyond government programs, since commercial partners and robotics firms involved in payload delivery could see new demand. Any societal payoff, however, remains speculative until the mission returns data.