It has one large continent, and thousands of islands across its one giant ocean.
The planet has thirteen moons, albeit all low-albedo, making the night very dark. The satellites are all assumed to be alien artifacts due to their consistent spacing in the same orbit.
It is the first planet outside the Sol system colonized by humans, sought after because of its considerable stores of lithium. The mining crew of the Barbapiccola formed the settlement First Landing and claimed the planet, naming it "Ilus", after travelling through a Ring in the slow zone. These men and women were refugees from the Ganymede incident, desperate for a new place to call home. After a year in space travel, they finally found and settled Illus.
However, the United Nations, who christened the planet New Terra, had given its lithium mining charter to the private Earth-based corporation Royal Charter Energy. The UN knew of Ilus previous, but only took up a recent interest due to the mining potential that was previously overlooked.
Traveling to the planet from Ceres takes about eighteen months for the aging Edward Israel. It takes the Rocinante about 73 days under heavy burn to make it there from Medina Station in the slow zone.
The planet itself also has traces from an ancient and advanced alien presence in the form of ancient ruins located in a visible distance from First Landing. At the time of Cibola Burn, however, the planet's indigenous (at least nocturnal) fauna is mostly known to consist of animals similar to birds and lizards, such as the mimic lizard. Despite this, there are many hostile creatures and elements on Ilus that do not make it the most ideal place for humanity. "Death Slugs", which come out after rainy periods are deadly to humans, and are numerous.
During the U.N "invasion" of the planet, to reclaim it from the refugees, hundreds of scientists, and researchers are sent in to review, study and find any evidence that the refugees have interfered with the natural fauna and biosphere of Illus. One of the main members of the science teams is Elvi Okoye.
While the Investigator connects to the planet he describes alien structures on the planet, like libraries once used by the protomolocule creators, observatories in the mountains, habitation zones deep under rock and power cores deep underneath the oceans.