This comes from his famous reflection on a photograph of Earth taken by the Voyager 1 space probe from 6 billion kilometres away, in which Earth appears as a tiny blue pixel. Sagan wanted to emphasise how fragile our world is. He emphasises that we cannot rely on aliens or external cosmic forces to solve human crises (such as war or climate change); it is entirely up to us to protect our planet and treat each other with greater kindness.















