NASA has selected a project to investigate a football-field-sized hole on the moon that may open into a cavern able to shield future astronauts from harsh radiation and temperature swings.
The space agency tapped the Planetary Science Institute to lead the Geophysical Instruments for Marius Lunar Pit Investigation, known as GIMLI, after the team announced the project on Monday. The target is the Marius Hills Pit, an opening in one of the moon’s most volcanically varied regions that Japan’s SELENE spacecraft first spotted in 2009.
Daily Mail reporting describes an opening roughly the size of an American football field and about as deep as a 10-story building. Scientists want to know whether it leads to a lava tube or larger underground structure that could one day protect crews living and working on the lunar surface.
About 300 pits have already been identified across the moon. Marius Hills stands out because its walls expose layers of regolith and old lava flows, giving researchers a natural cutaway into the moon’s volcanic past while they hunt for usable shelter.
NASA has said a confirmed cavern could guard astronauts from radiation and dramatic temperature swings. Those hazards are not abstract. Radiation levels on the lunar surface run roughly 2.6 times higher than on the International Space Station and about 200 times higher than on Earth. The station orbits only about 250 miles above our planet; the moon offers no comparable magnetic shield.
That math matters as the United States prepares to put people back on the surface for longer stays. Under current plans, Artemis IV in 2028 would send two astronauts down near the South Pole for about a week of science before they climb back to lunar orbit and head home. Any structure that cuts exposure would turn a short visit into something closer to a workable outpost.
GIMLI will not settle for pictures taken from overhead. The plan combines ground-penetrating radar, seismic sensors, and a device that measures the local gravitational field so the team can map what sits below the rim. Researchers intend to examine the pit from the lunar surface and study the exposed wall layers directly.
Than Putzig, associate director and senior scientist at the Planetary Science Institute, tied the approach to unfinished business from the last American landings.
"It's long been a desire of mine to reintroduce intentional active-source seismic methods to planetary science, as it has essentially not been done since the Apollo astronauts conducted the first seismic surveys on the moon."
He added that pairing those methods with radar and gravity readings raises the odds of a clear result.
"Combining that method with ground-penetrating radar and gravity measurements makes it all the more exciting, as these methods together will allow us to get a much better understanding of subsurface properties, including the anticipated detection of a lava tube extending away from the Marius Hills Pit."
Gareth Morgan, a PSI senior scientist and deputy principal investigator on GIMLI, framed the payoff in plain geologic terms.
"Confirming a substantial lava tube would give us an insight into how volcanism operated on the moon."
He noted the Earth parallel that makes the search more than a stunt.
"Lava tubes are a common feature of basaltic volcanism on Earth, so identifying them on the moon means we could use knowledge of such terrestrial caves to better understand lunar history."
The team also plans to study more than the possible underground structure itself, using the pit walls as a record of how lava once moved across that region.
No cavern has been confirmed at Marius Hills. Detection remains the goal, not a finished finding. Funding figures, the exact lander, and the flight assignment for the instruments were not detailed in the announcement package. What is clear is the sequence: a 2009 discovery, a fresh instrument suite selected by NASA, and a 2028 Artemis timeline that will put Americans back on the surface whether or not this pit pan out.
Lava tubes on Earth already show how basaltic flows can leave stable voids. If the moon offers the same architecture, crews could place habitats under rock instead of hauling every inch of shielding from Earth. That is engineering common sense, not science fiction. It is also the kind of hard-nosed problem American space programs used to treat as routine: measure the hazard, map the ground, and build for the people who have to live with the result.
GIMLI’s mix of radar, intentional seismic shots, and gravity data is designed to settle the question with instruments rather than wishful overlays on orbital photos. Putzig’s point about Apollo is the right one. The United States once did this work on the moon; the tools are now better, and the need for real shelter is higher if longer stays are more than press releases.
When the next boots hit the regolith, radiation and temperature will not care about mission patches. A verified tube at Marius Hills, or a hard no, beats another decade of guessing from orbit.
