The Toposphere Project is an incomplete Dyson sphere surrounding the planet of Jupiter which provides living space for the Jovians. Construction began on it in ES 316 and 13 of the 16 Jovian moons were consumed to provide materials for the project. One of the sources of competition between the Jovians and Venusians is exploitation of the Saturnian moons and the asteroid belt for use in their respective terraforming efforts.