Pale Blue Dot starts with an expanded version of Sagan’s famous speech and then deconstructs any notion that the Earth, or the human species, has any privileged position in the cosmos. From the idea that the Earth is the centre of the universe to the idea that humans were created as its caretakers. In each chapter, Sagan starts with a well-defined thesis and then walks us through his thinking, never straying into technical arguments, but keeping that open, everyman approach that he was so well-known for.
He talks about the planets visited by the Voyagers before turning to the idea of human settlements on other worlds in our solar system. He discusses (and dismisses) a number of possible reasons for human space exploration and settlement, keeping his strongest arguments back for the final chapters. In these, he strongly argues that over geological time, there will be events that will shatter a civilisation based solely on a single planet, and, for the safety of our species, we need to migrate – not only to the rocky worlds, but to near earth asteroids and the Oort cloud – to small worlds that we could learn to move around, to avoid any collisions with the mother world, and, in the final chapter, he lets his imagination soar and imagines a human civilisation that spans the galaxy.
Sagan’s ideas, and the words in which he expresses them, are delightful and awe-inspiring. He rightly predicts the idea of robotic explorers of Mars sending back such detailed pictures that you could sit in your bedroom, and virtually travel over its surface. While I sometimes think he thinks better of our species than we deserve, maybe the events of the second half of the 2010s have just made me cynical. And if you want to read something completely lacking in cynicism, and brimming with hope and optimism then this is it.
