The Skylab 4 crew was experiencing a phenomenon known as the overview effect, which refers to the intense emotional reaction that can be triggered by the sight of the earth from beyond its atmosphere. Sam Durrance, who flew on two shuttle missions, described the feeling like this: “You’ve seen pictures and you’ve heard people talk about it. But nothing can prepare you for what it actually looks like. The Earth is dramatically beautiful when you see it from orbit, more beautiful than any picture you’ve ever seen. It’s an emotional experience because you’re removed from the Earth but at the same time you feel this incredible connection to the Earth like nothing I’d ever felt before.”

What’s most remarkable about the overview effect is that the effect lasts: the experience of awe often leaves a permanent mark on the lives of astronauts. A new paper by a team of scientists (the lead author is David Yaden at the University of Pennsylvania) investigates the overview effect in detail, with a particular focus on how this vision of earth can “settle into long-term changes in personal outlook and attitude involving the individual’s relationship to Earth and its inhabitants.” For many astronauts, this is the view they never get over.