A planned trip to the moon ends in failure when a space mission is diverted and lands on Mars. As the team explores the red planet, they discover a once-great civilization whose devastation by atomic attack has transformed it into a race whose appearance and behavior resemble that of prehistoric humans. Despite its shoddy special effects (which were later reedited by director/film collector Wade Williams for the film’s reissue) and questionable scientific research, this low-budget classic conjures a noble image of intergalactic life that became a big commercial success.