For several decades, science teachers have used bottles for classroom projects designed to teach students about biology. A model terrarium enclosed in a glass bottle was described in the 1975 edition of Science and Children (Ochs and Brock 1975). Since then numerous adaptations of the “bottle biology” idea have been developed. This article describes an inexpensive model of a pond ecosystem that demonstrates the interaction between the geosphere, hydrosphere, atmosphere, and biosphere. Although this activity is reminiscent of other bottle biology projects, the Earth System Science Project was designed to fit specifically into an Earth science curriculum.