Out of the Silent Planet

I was reading this book by C.S.Lewis. Some things that I stopped to think....
Earth light. Now thats a new word not difficult to understand.
Ransom wonders how the moon is bigger than he knows it to be. All fantasy whatever it may have, has to be viewed by the people of this earth.
A line about his one foot in the dark, unknown seeming heavier and the other one light just is too packed a sentence...