In the 1950’s, ‘space-beings’ surveying the Earth, were generally described as having physical perfection and originating from a highly civilized society, very like the ‘gods’ or ‘angels’ of mythology. Depicted in Sumerian and Mayan art as humans of large stature, but of a different race to the indigenous people. They possessed telepathic abilities and ‘superhuman’ qualities, but without exuding superiority.
If spaceships have been visiting Earthlings, since hoary antiquity, it would imply they have a vested interest in our planet, or perhaps even originate here, the descendants of sentient beings whose technology far surpassed ours, and also exist on (or in) other planets in our Solar System. If the Earth is hollow, these ‘gods’ would certainly have been aware of that fact and likely had access to this inner-world.