Retro-futuristic aliens

“Men in Black,” “Prometheus,” and Fictional Aliens : The New Yorker: Don't you just love nutjobs? The world's literary history would be so much duller without the occasional off-his-rocker dreamer.
"It was only after Jean-Baptiste Lamarck’s and Charles Darwin’s theories of adaptation and natural selection gained wider acceptance, in the nineteenth century, that writers began to speculate in earnest about the sorts of creatures that might flourish in environments beyond Earth. According to Brian Stableford, writing in the Encyclopedia of Science Fiction, the definitive reference on the genre, Camille Flammarion was the first author to present a popular fictional portrait of truly alien life-forms. Flammarion was a French astronomer whose metaphysical interests, if he were pursuing them today, would be labelled New Age. (These beliefs damaged his scientific reputation, but they did lead to a friendship with Arthur Conan Doyle, who shared a fascination with spiritualism.) In 1864, Flammarion wrote a nonfiction book, “Real and Imaginary Worlds,” expressing his conviction that there was life on other planets, and eight years later he produced “Lumen,” a peculiar fictional work in which the title character, a scholar, relates the myriad wonders of the universe to a disciple."