In all our searching, the only thing we’ve found that makes the emptiness bearable is each other.

Carl Sagan was one of the greatest science communicators of the last century. A planetary scientist and astrophysicist, he had a gift for explaining complex scientific concepts to the general public. He was also acutely aware of humanity’s place in the universe. It was Sagan who suggested to NASA that the Voyager 1 space probe should turn its camera around to snap one last photo of Earth before it sped away into interstellar space, from a distance of 3.7 billion miles away. The resulting photo, which shows the Earth as a tiny speck against the vastness of space, is known as the “Pale Blue Dot.” The image had little scientific value, but its significance was profound: It gave humans a perspective of our world out there in the vast emptiness — and us, as Sagan put it, as “momentary masters of a fraction of a dot.”