The Tayac system is a small planetary system in the United Empire of Earth (UEE), made up of a G-type main sequence star, a terrestrial planet, a gas giant, a dwarf planet, and an asteroid belt. Starting in 2546, Dr. Thessaly Tayac, for whom the system is named, conducted a long-term research project on Tayac I to explore the possibility of weaponizing the terraformation process and technology. Thanks to his experiments and those of his successors, the surface of Tayac I has become too unstable to support permanent terraforming. Tayac is best known as the home of the Ark, a neutral library and archive built for the use of all civilizations.