Submission + - First underground cave photographed on the moon (wired.co.uk) 1
Lanxon writes: High-resolution images have confirmed for the first time the presence of an underground cave on the moon's surface. Images taken by the Lunar Reconnaissance Orbiter camera reveal that what previously appeared to be a lunar pit in the Marius Hills region is in fact the entrance to a lava tube, with the cave floor visible through a collapsed ceiling, or "skylight".