Is There a Giant Cave Under the Moon's Surface? NASA's New Plan to Find Out
NASA wants to know whether there is a huge natural cave under the Moon's surface. On September 30, 2026, the agency announced three new science investigations for its Moon Base programme, and one of them is a lava tube hunt.
What NASA announced
NASA selected three payload suites through its PRISM programme (Payloads and Research Investigations on the Surface of the Moon). They will fly to the Moon on commercial landers under the CLPS initiative. NASA says the instruments will help researchers understand lunar resources, map natural shelters and assess environmental hazards ahead of astronauts.
The three are:
- LEMS-SP, a long-term station that monitors micrometeoroids, volatile gases and moonquakes near the South Pole, to assess hazards for Moon Base hardware.
- DISCO, which will make the first direct on-the-ground measurements of ice hidden in tiny permanently cold spots, and study how stable the surface is.
- GIMLI (Geophysical Investigation for Mapping Lunar Interior), the lava tube hunter.
What is a lava tube?
On Earth, a lava tube forms when the outside of a lava flow cools and hardens into a crust while hot lava keeps flowing underneath. When the eruption ends, the lava drains away and leaves a hollow tunnel. NASA says GIMLI will help explain how volcanism worked on the Moon, and the same process produces such tunnels on Earth.
What GIMLI will do
GIMLI will be placed at the Marius Hills Pit, a hole on the lunar surface. NASA says it will scan beneath the surface to see whether the pit leads into a large underground lava tube. Its principal investigator is Dr. Nathaniel Putzig of the Planetary Science Institute.
According to a TechTimes report on the selection, the payload combines ground-penetrating radar, an active seismic source, a gravimeter and cameras. Radar and gravity can show where rock is missing, and the seismic waves help show what lies below. TechTimes adds that this would be the first deliberate generation of seismic waves on the Moon since Apollo 17 in 1972. The pit is about 65 meters wide, according to the same report.
Why a cave would matter
The Moon's surface has little protection from radiation and tiny meteorite impacts, and its temperature swings are extreme. NASA says confirmed lava tubes could offer ready-made shelter with thermal stability and shielding, and could change how habitats are planned. It has not confirmed that such a tube exists. That is what the mission is meant to find out.
Sources
- NASA, "NASA Adds New Science Investigations for Moon Base", September 30, 2026: https://www.nasa.gov/news-release/nasa-adds-new-science-investigations-for-moon-base/
- TechTimes, "NASA Picks Lunar Lava Tube Hunt: First Surface Seismic Survey Since Apollo", October 2, 2026: https://www.techtimes.com/articles/328490/20261002/nasa-picks-lunar-lava-tube-hunt-first-surface-seismic-survey-since-apoll
Facts checked: October 3, 2026.