The result is a remarkably rich description of
students’ conceptions and misconceptions about the paths taken by projectiles and what keeps satellites
and planets in their orbits. The article will start with a brief history of how these ideas developed in the
history of science and an overview of what students are expected to learn at various age levels according
to the Benchmarks for Science Literacy (American Association for the Advancement of Science [AAAS]
1993) and the National Science Education Standards (National Research Council [NRC] 1996). It
concludes with answers to the following questions and recommendations for teachers and curriculum
developers.