In August of 1835, a New York newspaper called The Sun published a story claiming that the British astronomer Sir John Herschel, using a powerful new telescope in South Africa, had discovered life on the moon. Not signs of habitability. Life. Lush forests, rushing rivers, herds of blue unicorns, bipedal beavers who carried their young under their arms, and a race of winged humanoids — bat-men — who lived in communities, built temples, and appeared to practice agriculture.

The story ran across six articles over two weeks, cited a real astronomer, and deployed the vocabulary of nineteenth-century science with enough precision to sound credible. The New York Times called the discoveries probable. Religious groups began planning missionary expeditions. The Sun's circulation shot from eight thousand to nearly twenty thousand copies a day, making ...