Expit Aposi was a very small Ecumenopolitic planetoid moon orbiting a Gas Giant in the Zenoit system. In 2401 the settlement was established with the central district covering 536 km2. It was the only Encumenopolis in the Federation but was sparsely populated, only 18 million Centurians and 7 million aliens inhabited it. The moon had a small surface area, being almost the size of Pluto. This allowed for the massive ecumenopolis on it to be formed. It was a major tourist attraction and strategic center.