Following the discovery of unknown artifacts and structural anomalies during Apollo 11 & 12 space missions, there has been great speculation that NASA was aware of other civilizations on the moon.

For centuries astronomers have observed transient lunar phenomena (TLP) – lights that appear and, in some cases, move across the lunar surface. In 1968 NASA published a report describing hundreds of TLP sightings. With the recent discovery of collapsed lava tubes by Lunar Reconnaissance Orbiter and other probes, there is growing speculation that vast subterranean spaces exist below the lunar surface suitable for settlement and manufacturing. In this program we consider the possibility that some TLP may originate from within the moon and that collapsed lava tubes may be a more likely place to find evidence of extraterrestrial activity than on the surface.

Thanks to Cliff Dunning http://www.earthancients.com/
https://twitter.com/cliffdunning