Early in 2010, a group of year 11 students (age 15-16) studying GCSE (General Certificate of Secondary Education) Astronomy at The Radclyffe School, Oldham, in the UK, teamed up with a similar age group from Tianyi High School, Wuxi City, in China, to undertake a joint astronomy investigation. This article outlines the outcome of the first stage of the project and is designed to provide the reader with data and equations that can be used for physics- and/or mathematics-based investigations. Using data extracted from the scientific literature, students were tasked with deriving a theoretical mathematical model that could be used to predict the depth of simple lunar primary and secondary impact craters. (Contains 8 figures and 3 tables.)