Japan’s Kaguya (SELENE) orbiter confirmed the existence of a massive underground cave, or lava tube, on the Moon in 2017, following its initial discovery of a vertical pit (skylight) in 2009. Located in the Marius Hills region, the cave is roughly 50 km (31 miles) long and 100 meters wide, offering potential shelter for future lunar bases
I don’t understand the dimensions. If it’s 100m wide (I assume the diameter of it as seen from the top) then what is 50km long ? is it 50km deep ? I don’t think so we wouldn’t see the bottom of it sunlit. So what is it ?
edit more details over here :
https://insights.globalspec.com/article/6934/nasa-and-jaxa-find-moon-tunnel-ideal-for-first-moonbase
Its tube shaped, parallel to the surface. Not just the hole in the picture
oh ok I understand now. Cheers