Sentarion Sentarion was a desert planet . It was known for its universities and scholarship . Astronomical data . Sentarion orbited a star that was larger than Earth ' s and orbited it more closely , making it very hot . It was smaller than Earth and had a richer atmosphere ; insect s grew to greater sizes . Crystalline rocks found on the planet could be used for solar - energy panels . Sentarion was largely uninhabited , though there were several species of intelligent insects on the planet . Known species included the Sentarii ( the rulers ) , the Harrubtii ( the religious zealots ) , a grasshopper - like species ( the middlemen ) and a beetle - like species ( the labourers ) . There were also great variations within these castes . ( PROSE : " Shakedown " ) Culture . Though there were several species of insects on the planet , they tended to share a similar culture . The inhabitants of Sentarion were pacifists , except for the Harrubtii . They led simple lives , focused on the pursuit of knowledge . They had vegetarian diets , opposed the drinking of alcohol and had few comforts in their dwellings . They didn ' t socialise with others , working during the day and sleeping during the night . Despite this , they weren ' t opposed to alien s doing otherwise . The insects of Sentarion were a religious people , especially the Harrubtii . They worshipped the " Shining Ones " , who were actually the Rutans . Most discussion on the Rutans was taboo , sometimes leading to death by the Harrubtii . ( PROSE : " Shakedown " ) History . Early in their history , the insects of Sentarions fought endlessly with each other . At one point , the Rutan Host arrived on the planet through a wormhole . They intended to use the planet as an escape route and so modified the native species , making them intelligent and loyal to the Rutans . The Rutans were known as the " Shining Ones " and were worshipped as god s . Though the Rutans eventually left the planet , they made the Sacred Compact with the Sentarii . If the pact was fulfilled , the Rutans would return one day . The insects of Sentarion used the knowledge they were given and developed technology , such as the ornithopter s which they used as vehicles . Unlike many such civilisations , they skipped polluting energy sources like oil and used solar powered - based electricity . The villages grew and expanded until they formed the massive University of Sentarion . They soon became renowned as scholars and intellectuals . At some point in the 26th century , Bernice Summerfield came to Sentarion , looking for information on the Rutans . The Harrubtii constantly dogged her , but she was able to find the connection between their planet and the Rutans . When she went into the sacred Temple of the Shining Ones , she was trapped ; she would be killed for her blasphemy but her death would foul the temple . When Karne arrived on the planet , he tried to open the wormhole above the planet . He was followed closely by the Seventh Doctor and his allies , and then by Commander Steg . Commander Steg forced the Doctor to open the wormhole and sent a War - Wheel to Ruta III to kill the Rutan Queen . The Doctor was able to reverse the polarity of wormhole , meaning the War - Wheel would never leave the wormhole . The wormhole was sealed permanently . ( PROSE : " Shakedown " )