Risqué cover art: Cyril Judd’s novel Sin in Space

A few weeks ago, Charlie Jane Anders of the SF blog io9 posted a gallery of risqué cover art. One of the covers was Sin in Space: an Expose of the Scarlet Planet, a revised novel by Cyril Judd (a joint pseudonym used by Cyril M. Kornbluth and Judith Merril) that was published in 1961 by Beacon Press, a publisher which was known for "sexing up" books to improve sales. "A rocketing, sensational exposé,” Sin in Space was largely published in 1952 by Dell Publishing under the less racy title Outpost Mars. Note the difference between the front and back covers of the two books.