Underground cave found on moon (1/2)

Photo released on July 15 shows the Mare Tranquillitatis pit as seen by NASA's Lunar Reconnaissance Orbiter. (Photo/VCG)

Researchers have found evidence for a substantial underground cave on the moon that is accessible from the surface, making the spot a prime location to build a future lunar base.

Photo released on July 15 shows the Mare Tranquillitatis pit as seen by NASA's Lunar Reconnaissance Orbiter. (Photo/VCG)