Intergalactic Sci Fi Raygun
El Gato Gomez- Mid Century Modern Retro Futurism
Michael Whelan - Time and Again (1970s)
The Star Beast by Robert Heinlein. NEL 1972. Cover art Jan Parker by pulpcrush, via Flickr
Art by H.J. Ward - Spicy Mystery March 1941
educational comic book, 1953. Perfectly normal stuff going on here.
That Glow in the Sky
Cover illustration for Galaxy Science Fiction (April 1959).