Well?...Those of you who believe in Lunar lava tubes/tunnels/caves may not have long to wait for evidence, for or against.
The Japanese Lunar orbiter, KAGUYA, has a Lunar Radar Sounder (LRS)
experiment that is working just fine; thank you very much.
It has already returned data.
Its radar signals have penetrated upto 500 meters below the surface.
If the Moon has caves, tunnels (lava tubes) we may finally have definite
evidence in the coming months to show whether those tunnels/tubes or caves
actually exist there.
Personally, I'm skeptical....I think the Lunar surface was battered so intensely
by meteorites/asteroids/comets that any caves or tunnels would have been
collapsed or flattened outright.
So, any bets one way or the other?
Jacob