Solar eclipses, supermoons, a star-studded night sky — for us earthlings, looking up into space can be a transformative experience.
But what about the other way around? What is it like to see the entire earth from space? Only a select group of astronauts have had that grand opportunity.
"There was actually a physical moment in time when we answered a puzzle — something that's puzzled us throughout the whole of human history: What did the Earth look like from the outside?" says science historian Christopher Potter.