The Tenth Planet of malevolent cyborgs that became a recurring adversary in later "Doctor Who" stories. The "tenth planet" in the title makes reference to a fictional lost planet in Earth's Solar System; at the time of production, the Solar System was generally held to consist of nine planets, prior to the redesignation of Pluto as a minor planet. "The Tenth Planet" is an incomplete "Doctor Who" serial – one of many serials that were affected by the BBC's policy of wiping archived programmes in the 1960s and 70s. Only three of the four episodes are currently held in the BBC archives; the
The Planets mysterious and distant as Neptune. Holst then scored the suite for a large orchestra, in which form it became enormously popular. Holst's use of orchestration was very imaginative and colourful, showing the influence of such contemporary composers as Igor Stravinsky and Arnold Schoenberg, as well as such late Russian romantics as Nikolai Rimsky-Korsakov and Alexander Glazunov. Its novel sonorities helped make the work an immediate success with audiences at home and abroad. Although "The Planets" remains Holst's most popular work, the composer himself did not count it among his best creations and later in life complained that its popularity had