A Survey and Analysis of College Students' Understanding of Planet Formation before Instruction

The topic of solar system formation has become essential to the teaching of astrobiology due to the discovery of more than 3700 exoplanets, some orbiting within their host star's habitable zone. The architecture of planetary systems is more easily understood when students are able to comprehend how solar systems form. There has yet to be a study that addresses the topic of planet formation at the college level using a large sample of introductory astronomy students. We collected responses from students in 13 introductory astronomy and planetary science courses (n = 1050) at the University of Arizona, who each completed 1 of 6 short-answer questions on the topic of planet formation. The questions were administered on the first day of the Fall 2016 and Spring 2017 semesters before any relevant material was taught. After analyzing their responses, we found that the most common misconception students held was that our Solar System formed as a direct result of the Big Bang, but a substantial percentage of students lacked a more general understanding of fundamental astronomical topics (gravity, definitions of a planet and solar system, density, and the physical processes associated with solar system formation). This lack of foundational knowledge prevented students from explaining and understanding the process of planet formation at a scientific level.