What happened
NASA has selected GIMLI to investigate whether Marius Hills Pit connects to a large underground lava tube. In this three-minute Newstro Science & Space report, we examine real Lunar Reconnaissance Orbiter images, explain how lava tubes form, and show how radar, seismic sensors and gravity measurements can investigate the subsurface.
The Planetary Science Institute leads GIMLI — Geophysical Instruments for Marius Lunar pit Investigation. This report covers NASA’s September 30, 2026 announcement, updated October 2, and PSI’s October 1 release. GIMLI is a planned payload, not a completed cave survey. Neither selection announcement specifies a deployment date.
Pit dimensions shown are NASA’s LRO-based description: approximately 34 m deep and 65 × 90 m wide. These describe the pit, not the size of a connected cave. Cutaway, shelter and instrument graphics are explanatory illustrations, not a measured cave map or images of actual GIMLI flight hardware. The full connected underground extent remains a research question.
Every statement is attributed to the cited reporting. Visuals marked “file photo” or “illustrative” do not depict the events described unless stated.