Sir Winston Churchill is best known as a public speaker and for his time as Prime Minister of Britain during the Second World War, but he had many other facets. During his life he was a soldier, war correspondent, Member of Parliament, First Lord of the Admiralty, historian, painter, and now we find out, a science pundit. In a comment piece in Nature, astrophysicist and author Mario Livio discusses a recently rediscovered 1939 essay by Churchill in which he discusses the possibility of life on other planets and the exploration of the Solar System.

Churchill was an internationally famous man even before his wartime career, but it was hardly smooth sailing. During what are now called his "wilderness years," Churchill was banished from the political landscape after falling out with the Conservatives in the wake of the general election of 1929. In disgrace and his political career seemingly over, he turned his attention to study and writing. During this time, he wrote a biography of the first Duke of Marlborough, the multi-volume History or the English Speaking People, and a book of biographical essays, as well as many popular magazine articles.

These articles reflected Churchill's broad range of interests and included some surprising predictions of the year 1981, which were published in 1931 in The Strand Magazine and reprinted in Popular Mechanics under the title "Fifty Years Hence." In this piece, he discussed the possibilities of fusion power, underground farming, lab-grown meat, and even the potential downsides of cloning.

According to Livio, this shouldn't come as a shock because Churchill took a strong interest in science, having read Darwin's On the Origin of Species in 1896 and being in contact with many of the great minds of his day, including the physicist Frederick Lindemann, radio astronomy pioneer Bernard Lovell, and others. This interest and understanding was demonstrated during the war when Churchill encouraged many scientific projects, like centimetric radar, jet propulsion, and a top secret weapon project that soon moved to America and became the atomic bomb.

Livio relates that this scientific approach to war so exasperated Air Chief Marshal Arthur "Bomber" Harris that he complained, "Are we fighting this war with weapons or slide rules?"

Churchill replied, "Let's try the slide rule."

But Churchill's interest in life beyond our planet was overlooked by scholars until Timothy Riley, the director of the US National Churchill Museum in Fulton, Missouri rediscovered an 11-page typewritten manuscript by the great man entitled "Are We Alone in the Universe?" According to Livio, this was first written in 1939 and was probably meant for the popular News of the World newspaper, but was never published. However, he revised it in the late 1950s and it passed into the hands of his publisher, Emery Reves and, eventually, to the museum. Since then, it has never been published or given over to academic study.

Livio says that Churchill's thoughts on extraterrestrial life are remarkably modern. He recognized that it's unlikely that the Earth is unique and that for any sort of complex form of life to exist, it must have liquid water – if only because no viable alternative is known. Churchill goes on to talk about what is now called the Goldilocks or habitable zone – the orbital distance around a star where it's possible for liquid water to be found on a planet's surface. Additionally, he stresses the importance for a body to have enough gravity to prevent water and air from escaping into space. From this, he concluded that in our solar system, only Venus and Mars had any chance of harboring life as we know it.

It's an essay that is in many ways reflected popular science of the day, but Churchill goes further as he talks about other planets in our galaxy. In those days, understanding of the Universe outside the Solar System was still in its infancy, and the idea that the other galaxies were giant star clusters like the Milky Way and not gas clouds was still relatively new.

Even how the planets formed was the subject of rival theories. One by astrophysicist James Jeans was that planets were only formed when two stars passed close to each other and tore matter out of one another. But Churchill was unconvinced by this and favored the modern idea that the planets coalesced out of a disk of dust and gas around what we would now call a protostar. This meant that the Earth was unlikely to be exceptional and that there may be many planets outside our solar system capable of supporting life, though we may never know because of the distance between the stars.

Livio says that Churchill was more optimistic about travel in the Solar System.

"One day, possibly even in the not very distant future, it may be possible to travel to the Moon, or even to Venus or Mars," Churchill wrote.

The essay finishes with Churchill saying, "[W]ith hundreds of thousands of nebulae, each containing thousands of millions of suns, the odds are enormous that there must be immense numbers which possess planets whose circumstances would not render life impossible. I, for one, am not so immensely impressed by the success we are making of our civilization here that I am prepared to think we are the only spot in this immense universe which contains living, thinking creatures, or that we are the highest type of mental and physical development which has ever appeared in the vast compass of space and time."

There was no announcement if the essay will be published, but here's hoping.

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