Star Trek (with a weird, hybrid U.S.S. Enterprise), Laserblast (represented by David Allen's stop-motion aliens) and the Universal sci-fi classic, This Island Earth, collide in this cool magazine poster from the late 1970s. I'm sure one of you Star Kids out there can identify where this poster originally appeared and the artist who painted it... because I have no idea!
The artist's signature is indecipherable, unfortunately, and the style isn't instantly familiar.
If I had to guess as to its origins, I'd say it looks like something from the UK's Starburst or maybe the short-lived Science Fantasy Film Classics, or maybe Fantastic Films.
UPDATED: I knew I could count on you folks! Star Kids Martin Kennedy and Glen Mullaly have both identified it as being the work of John Allison. It appeared in Science Fantasy Film Classics #3 from the Summer of '78 (the one issue I didn't have!). Looks like my guess wasn't that far off. Thanks, guys!