Extraterrestrial: The First Sign of Intelligent Life Beyond Earth

by Avi Loeb

In 1939, as the world was collapsing around him, Churchill penned an article titled “Are We Alone in Space?” He never published it; the confluence of events that would bring him to the apex of his political influence would also sweep this essay aside and bury it for decades. A war was fought and won before Churchill, once more out of political fashion in the United Kingdom, revisited his article. In the 1950s, he gave it the more accurate title “Are We Alone in the Universe?” But it still sat unpublished at the time of Churchill’s death, and it entered the U.S. National Churchill Museum archives unknown and uncommented upon until its discovery in 2016. It is a shame that Churchill’s unusual essay was never published, for it contains ideas that were well ahead of their time and a sense of perspective that was sorely needed then, as it is now. Churchill evinced the modesty of a generalist as he wondered how unique the Sun and our planetary system might be, writing, “I am not sufficiently conceited to think that my sun is the only one with a family of planets.” He was also astute. Decades before the discovery of exoplanets, Churchill concluded it was reasonable to believe that a large number of planets existed “at the proper distance from their parent sun to maintain a suitable temperature,” had both water and atmosphere, and so could potentially support life. Indeed, given the expanse of space and the number of suns in it, he wrote, “The odds are enormous that there must be ...