“The overview effect is when you’re looking through the cupola and you see the Earth as it exists with the whole universe in the background. You see the thin blue line of the atmosphere, and then when you’re on the dark side of the Earth, you actually see this very thin green line that shows you where the atmosphere is. What you realize is every single person that you know is sustained and inside of that green line and everything else outside of it is completely inhospitable. You don’t see borders, you don’t see religious lines, you don’t see political boundaries. All you see is Earth and you see that we are way more alike than we are different.”
– Artemis II Mission Specialist Christina Koch
The Overview Effect: Astronaut Perspectives from 25 Years in Low Earth Orbit – NASA