Umud is the second-nearest, second-largest moon of Impendia, also having a sub-moon Umdu, which orbits it. This moon was the first point of contact with the Xollum-Xolrut System for non-squirrel species from Earth.
The Epos Impendian calendar starts with the arrival of Earth species to the moon, and the colonization of the desert above the Great Equatorial Rift. Some scholars and archaeologists believe that there was a city established at this site before the First Uplifting which is the first account of these early colonist groups scattering across the moon, along with accounts from various groups which differ on the subject of this 'city'.
In about 2200 E.I., considered the beginning of the Sublimium Age, technology and science gained widespread popularity in study and practice. With the increased mining of sublimium, colonists first built heavier-than-air ships capable of levitating above Impendia and then eventually larger and larger networks of vessels, stations, and eventually large colonies.
Along with large volcanic prominences and plateaus, Umud's most compelling feature is its equatorial rift, beneath which lies a vast field of sublimium-carbon crystal. An important feature of the sublimium, which is theorized to be the reason why the orbits of Umud and Umdu are as stable as they are, is its ability to levitate above the geology of Impendia's surface. In fact, scientists think that Umud's orbit around Impendia is more influenced by quantum locking between the sublimium beneath Umud's surface and Impendia's basinal geology, than it is by gravitation itself, which by many calculations would be impossible otherwise.