Scientific probes show wrong ideas in history

Looking back from the perspective of history of science(s), 'it is clear that many past conceptions about the earth ( that were also popularly accepted as truth for a long period of time) 'are wrong or without any factual foundation.'Space probes carried out in the last 60 years have shown that many ancient ideas on the universe are also questionable. Why or how were those wrong or questionable ideas formed and held, or defended so passionately 'by so many people on earth in the past ? What prompted or motivated great individuals, like Galileo Galilei to challenge the questionable beliefs and wrong ideas in their societies? Why did they not just accept the popular orthodoxies in their times ?