Introduction There is a particular kind of silence that descends when someone describes seeing Earth from space. Not the silence of emptiness — but of something settling, shifting, rearranging itself inside you as you listen. Astronaut Christina Koch has now made history twice over. First, for spending 328 days aboard the International Space Station. And now, as a mission specialist on NASA’s Artemis II — the first crewed lunar mission in more than half a century, which set