Exo III Exo III was the formerly inhabited third planet of its star system . The planet was the homeworld of the extinct . The planet ' s atmosphere was within safety limits by Federation standards . Its gravity was 1 . 1 of Earth ' s , to which it also used to bear a remarkable resemblance before its primary began to dim 500 , 000 years ago . ( ) History . As the star of the Exo system began to gradually dim , the average surface temperatures on Exo III eventually fell down to one hundred degrees below zero over the course of 500 , 000 years . The Old Ones , a humanoid species , fled their surface dwellings to the dark underground caverns to escape the inhospitable surface conditions . The species exchanged their open and free society for an increasingly mechanistic one . The Old Ones built over time more and more advanced android servants . They gave the androids a sense of pride in their abilities and a desire to survive . The Old Ones however became at some point fearful of their creations and began to turn them off . As their survival was threatened , the androids became able to exceed their programming . They murdered their creators in self - defense , causing the extinction of the Old Ones . In 2261 , famed Federation medical archaeologist Roger Korby was leading an expedition on this planet with his assistant Dr . . Korby sent messages back to the Federation through 2261 . Around that time , the expedition encountered the android Ruk , still tending the machines of the ancient civilization centuries after the extinction of the Old Ones . Among the machines , Korby discovered a still functional android duplicator . Korby had at the time lost the ability to use his legs and was freezing to death . He created an android duplicate of himself before his body died . When communications with Korby were lost , two further expeditions were sent to Exo III in an effort to locate the Korby expedition , but both failed to find them . In 2266 , the , under the command of Captain James T . Kirk , traveled to Exo III in a third attempt to learn the fate of the Korby expedition . Android duplicates of and contacted the " Enterprise " as it arrived on orbit . The crew later on discovered that both Korby and Brown had died on the planet five years ago along with the rest of the expedition . The android duplicate of Korby attempted to convince Kirk that the technology of the Old Ones should be used to secretly replace living people in the Federation with android duplicates . Since the duplicator could imprint the memories and the consciousness of the people being duplicated to the androids , the Korby - android was convinced that people would in time embrace the chance to live forever in android bodies . Kirk and Christine Chapel were not convinced , as the android duplicates had no sense of remorse or ability to experience genuine emotions . All the androids on the planet were destroyed in various conflicts that developed with them during the mission . ( ) In 2268 , the planetary profile chart of Exo III was displayed in one of the science lab s aboard the before the ship was pulled into the mirror universe . ( ; ) Appendices . Background information . This planet was originally to have been named " Exo IV " . Kellam de Forest found fault with this choice of name . He made a suggestion , included among a series of research notes ( dated ) , that the planet be renamed " Gamma Exo IV " . However , the name remained " Exo IV " . In another series of notes ( dated 11 May 1966 ) , de Forest recommended , " " The first number could be dropped . " " In the revised final draft script of " What Are Little Girls Made Of ? " , the surface of Exo III as seen from orbit was initially described thus ; " " The coloration of the planet suggests extremely low temperatures on the surface . However , not totally snow - covered . " " The script detailed a closer view of the surface by calling it , " " A semi - twilight landscape of barren wasteland buried in deep snow ; jagged ice peaks loom in b . g . against a dark and sinister sky . " " The caves of Exo III were represented with a set built on Desilu Stage 10 . ( " " , p . 81 ) According to " " ( p . 27 ) , Exo III was a . For the pre - remastered version of " What Are Little Girls Made Of ? " , the blue planet model for Exo III was first used for Rigel XII ( ) . This planet model would be used for Psi 2000 ( ) , M - 11 ( and ) , and Eminiar VII ( ) . For the remastered version of " What Are Little Girls Made Of ? " , a new planet model was created by CGI artist Max Gabl . Apocrypha . The recreation of Quark ' s Bar which was located in the " " attraction in the Las Vegas Hilton Hotel served an alcoholic drink called a Warp Core Breach that was reportedly served with ice crystals from Exo III . According to the novella " " , the mirror universe of the destroyed the last surviving member of the android society ( presumably Ruk ' s mirror counterpart ) on Exo III , who had likewise turned on their masters and killed them .