Binro
Binro (known as the Heretic) was an outcast living in the city of Shur. He realised the lights in the night sky over Ribos were not ice crystals, but in fact distant suns, not unlike the sun his own world circled. He took measurements, developed a rudimentary astronomy in the process and proved that the two seasons of Icetime and Suntime were due to the change in distance of Ribos from its sun.
His discoveries, however, ran contrary to Ribosian religious doctrine, which claimed that the change of seasons was due to an eternal battle between the Sun gods and Ice gods (which Binro did not believe in). Binro was branded a heretic.
Through a chance meeting with an off-worlder, Unstoffe, Binro learned that he was correct in his discoveries. Unstoffe told Binro the truth about his own origins and assured him that one day the people of Ribos would recognise that he had been right. Binro repaid this kindness by helping Unstoffe escape the Graff Vynda-K.
Attempting to warn Unstoffe of the Graff Vynda-K's approach, Binro was shot and died in Unstoffe's arms. (TV: The Ribos Operation)