Some of the strongest pieces of scientific evidence for the moon being hollow are that its density is too low for its size, and it rings like a bell, he cited. Some Russian scientists have proposed that the moon was artificially hollowed. The impact theory of the moon’s creation doesn’t seem accurate because there’s no evidence of a planetary body besides Earth hitting it.
An intelligent civilization might seek out a hollow moon or asteroid to “set sail on the cosmic sea,” and also use as a refuge to hide from more predatory species. The inside of such a body (he suspects the Martian moon Phobos is also hollow) could be mined out, and rotated to create gravity, he noted. A number of ancient civilizations such as the Maya spoke of a time when there was no moon, and Aristotle referred to an ancient race in Greece who said they existed before there was a moon in the sky. This suggests to him that the moon may have been maneuvered into its current position thousands or tens of thousands of years ago.