during its final two years of production beginning in 1954. Rocky Jones, Space Ranger was syndicated nationally for its two-year run from 1954 to 1955. Generally a superior program to most of the sci-fi series of the time, Rocky Jones was a victim of timing; by 1954, public interest was returning to the western genre. By the end of 1955, all of the episodic science fiction adventure series were gone from the airwaves. The anthology series Gradually, television producers realized that there was an adult audience as well as a young audience for science fiction. Television began to cater to a more cerebral brand of science fiction viewer, possibly inspired by the contemporary boom in literary science fiction by the likes of Isaac Asimov, or by the popularity of the allegorical science-fiction movies that were produced during the decade, such as The Day the Earth Stood Still. One of the stalwarts of science fiction television programming in its early decades was the anthology series, in which a completely new story would be presented in each episode, with new actors, settings, and situations. The only continuing link was the producers, the genre, and the series title. The first series of this kind was Tales of Tomorrow running for 85 episodes, between 1951 and 1953, it was meant to be the first science fiction show for adults. The next popular series was Science Fiction Theatre, a syndicated series that ran for 78 episodes between 1955 and 1957. Two years after its run finished, a much more popular and influential program in the same vein debuted on the CBS Network: The Twilight Zone, hosted by Rod Serling. The Twilight Zone began life as a one-off pilot, commissioned after the success of a science-fiction episode of the general drama anthology series Westinghouse-Desilu Playhouse. In its original form, the series ran for five years, from September 1959 until September 1964, with 156 episodes aired during that time. Presenting a vast array of science-fiction and horror concepts, its run included many memorable episodes whose imagery still lingers in American popular consciousness. One of its most enduring motifs has been its theme music, which is now recognized internationally. The Twilight Zone was the bedrock of the more grown-up science fiction that would be produced during the 1960s. It was shot on film (as was now standard for much American non-live television programs), well-produced, and featured imaginative writing.