Factual error: The adventurers witness Earth "rising" from behind the lunar horizon. Since the Moon is tidally locked, it always presents the same hemisphere toward Earth. Earth never rises or sets as seen from the Moon's surface; it stays stationary in the sky. No matter that no-one had travelled to the moon at the time - that fact can be deduced just by looking at the moon from earth, and noting that we only ever see one half of it.