
Japan’s Kaguya probe discovered a lunar pit that may be a skylight into a vast underground lava tube beneath the Moon’s surface
Japan’s Kaguya/SELENE lunar orbiter found a vertical pit in the Moon’s Marius Hills region that scientists believe may be an opening into an underground lava tube. Later studies using NASA Lunar Reconnaissance Orbiter data strengthened the idea that some lunar pits connect to subsurface caves or tunnels. These structures could one day matter for lunar bases because they may offer natural protection from radiation, micrometeorites, and extreme temperature swings.