2b95aab6_Marvel_Moon___Background__On_Moonless_Earth
[0] Phases [On Companion Earth] The Moon changes its appearance in the sky through a predictable pattern [Implication] Science advances more slowly without the repeating pattern of lunar phases to inspire astronomers to explain the phenomenon scientifically [On Moonless Earth] 
Venus and Mercury undergo phases, but these are not discovered before the invention of a telescope
Marvel Moon - Background
On Moonless Earth