In 1939, we knew much less about our solar system, so much less that these illustrations by Frank R. Paul may have really made people wonder about what strange life may be living on other planets. His drawings were some of the first images seen by science fiction writers Ray Bradbury, Arthur C. Clarke, and Forrest J Ackerman, making him one of the greatest influences on the early pieces in the genre. Using what little knowledge scientists had about the compositions of each planet, Frank R. Paul drew his predictions of what humans might find should they try to inhabit the other planets.[see_also]
He predicted Jupiter creatures would have to be enormous and super strong to cope with the tremendous gravity. Martians would have large ears with retractable eyes and noses to protect against freezing and communicate telepathically. Mercurians would only exist in insect form since they were so close to the sun. On Pluto, “the world of cold and eternal twilight would most likely be inhabited by winged-bat people with heavy protecting fur. See larger images of Frank R. Paul’s imaginative cover art on here.