William Shatner became the oldest person (90 years old!) ever to go into space in 2021. He spoke about the experience immediately after the fact. It was clear that it shook him up, but we would have no idea until 2022 when he released this statement in an op-ed for The Guardian. In it, he describes his experience of a well documented phenomenon experienced by many astronauts – the Overview Effect:

While I was looking away from Earth, and turned towards the rest of the universe, I didn’t feel connection; I didn’t feel attraction. What I understood, in the clearest possible way, was that we were living on a tiny oasis of life, surrounded by an immensity of death. I didn’t see infinite possibilities of worlds to explore, of adventures to have, or living creatures to connect with. I saw the deepest darkness I could have ever imagined, contrasting starkly with the welcoming warmth of our nurturing home planet.

This was an immensely powerful awakening for me. It filled me with sadness. I realised that we had spent decades, if not centuries, being obsessed with looking away, with looking outside. I played my part in popularising the idea that space was the final frontier. But I had to get to space to understand that Earth is, and will remain, our only home.

This highly emotional and moving experience is a well known phenomenon. Wikipedia gives us a good description of the Overview Effect:

The overview effect is a cognitive shift reported by some astronauts while viewing the Earth from space. Researchers have characterized the effect as “a state of awe with self-transcendent qualities, precipitated by a particularly striking visual stimulus”. The most prominent common aspects of personally experiencing the Earth from space are appreciation and perception of beauty, unexpected and even overwhelming emotion, and an increased sense of connection to other people and the Earth as a whole.

One of the earliest experiences was by Edgar Mitchell in 1971 as part of the Apollo 14 mission and the 6th man to walk on the moon. He was awarded the Presidential Medal of Freedom in 1970, but had this to say when looking at the Earth from his trip to the moon:

“You develop an instant global consciousness, a people orientation, an intense dissatisfaction with the state of the world, and a compulsion to do something about it. From out there on the moon, international politics look so petty. You want to grab a politician by the scruff of the neck and drag him a quarter of a million miles out and say, ‘Look at that, you son of a bitch.”