Plate Nº 42 · recorded October 2, 2026
Space & AstronomyReported finding
NASA Picks PSI-Led Team to Probe Possible Cave Beneath Lunar Pit
NASA has picked a Planetary Science Institute-led project, GIMLI, to search for a possible lava tube beneath the Marius Hills pit using seismic, radar and gravity instruments on the lunar surface.
By James Calloway4 min read863 words
In brief
- NASA selected the PSI-led GIMLI project to investigate whether a cave or lava tube extends beneath the Marius Hills pit on the moon.
- GIMLI will combine active-source seismic methods, ground-penetrating radar and gravity measurements to map the lunar subsurface — the first intentional active-source seismic survey since Apollo.
- Honeybee Robotics will build the instruments, and the lander and rover will come through NASA's Commercial Lunar Payload Services initiative; the Norwegian Space Agency provides the radar.
NASA has selected a proposal led by the Planetary Science Institute (PSI) to investigate whether a large underground cave extends beyond the opening of a lunar pit. If such a cave exists, it could one day serve as a shelter for astronauts, protecting them from the radiation and the extreme temperature swings that batter the moon's surface.
The selected project, called GIMLI — short for Geophysical Instruments for Marius Lunar pit Investigation — is led by Than Putzig, an associate director and senior scientist at PSI. The institute is partnering with Honeybee Robotics, which will build much of the equipment, and with the Norwegian Space Agency. The instruments will ride to the moon on a lander and rover provided through NASA's Commercial Lunar Payload Services initiative, a program that contracts private companies to deliver payloads to the lunar surface.
"GIMLI represents the type of ambitious planetary science that PSI was built to pursue," said PSI director and CEO Amanda Hendrix. "Than and his team are taking a scientific question we've been studying from orbit and have developed a way to investigate it directly on the moon. We're excited to have PSI leading this effort and to be partnering with NASA and Honeybee Robotics to learn more about the moon and its volcanic past."
What the team will examine
Observations from lunar orbit have provided compelling evidence that caves and lava tubes — hollow tunnels left beneath the surface — may exist under the moon. GIMLI's research will focus on the Marius Hills pit (MHP), a large hole in one of the moon's most volcanically diverse regions. Like other lunar pits, MHP may be an opening to these underground spaces, which may have formed during ancient volcanic activity when rivers of molten rock drained away and left empty channels behind.
GIMLI will let scientists investigate the pit directly from the lunar surface for the first time, rather than relying on orbital data alone.
"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," Putzig shared.
"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."
How the instruments will work
Active-source seismic surveying involves generating deliberate vibrations — in plain terms, shaking the ground in a controlled way — and recording how those waves travel through the subsurface. Different materials and empty spaces affect the waves differently, allowing scientists to build a picture of what lies below. GIMLI will combine this technique with ground-penetrating radar, which sends radio waves into the ground, and a gravimeter, an instrument that measures tiny variations in gravitational pull that can reveal hidden voids. Cameras will provide imagery of the surface and the pit walls.
Together, these instruments will search for an underground void extending from MHP and, if one exists, help determine its size.
Honeybee Robotics, a Blue Origin company, is providing project management services and building the seismic system, the gravimeter and the cameras. The company will also integrate all instruments onto the lander and rover and, together with PSI, will lead their operations on the lunar surface.
Science beyond the cave hunt
Even if GIMLI finds no cave or lava tube, the data could still answer an important question: how did the pit form in the first place? Measurements of the surrounding subsurface could clarify the origin of MHP and improve scientists' understanding of the geology and volcanic history around the site.
The team will also look beyond the pit itself. The region has a long history of volcanic activity, and the walls of MHP expose layers of regolith — the moon's loose, dusty surface material — and ancient lava flows that are usually hidden underground. Studying those exposed layers could reveal how lava traveled across the moon and whether long stretches of time separated individual eruptions.
Any underground spaces connected to the pit interest scientists for another reason as well: their interiors could preserve a record of the volcanic processes that shaped the moon.
"Confirming a substantial lava tube would give us an insight into how volcanism operated on the moon," explained Gareth Morgan, a PSI senior scientist and deputy principal investigator on the GIMLI program. "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."
Beyond PSI and Honeybee Robotics, the GIMLI team includes co-investigators 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.
It is worth keeping in mind that the existence of a cave beneath the Marius Hills pit, while supported by orbital evidence, remains unconfirmed until the instruments arrive and take their measurements. The mission's outcome will depend on what the lunar subsurface actually reveals.
via Phys.org Space & Astronomy (Source)