|Year length (PST)||20 years|
|Day length (PST)||50 days|
Source: Near Space, pg(s). 108
Ulthel's atmosphere consists mostly of hydrogen, helium and methane, tinted pink and lazily swirling over its atmosphere. For some reason, its upper layers contain enough oxygen to be breathable for most species.
Soon after the Gap, many governments and corporations, interested in harvesting Ulthel's natural gases, launched many explorations to it. Eventually, they all disappeared: some blinked out of existence, others just ceased communication with their homeworlds seemingly for no reason. Everyone reported that the planet, including previous structures, were uninhabited.
Later explorers started reporting enormous schools of ulthelim, which they considered to be indigenous fauna. Soon enough, they started to hear the ulthelim calling to them to become one with them and the planet. Such reports are always the last ones before these visitors vanished as well. Currently, most explorations to Ulthel have ceased.
According to most scientists, the ulthelim are transformed from explorers who dared enter Ulthel's atmosphere. This theory is reinforced by how the number of ulthelim sightings all correalate to the number of people who visited Ulthel. In all pleas, ulthelim refer to themselves and Ulthel as a single entity. It is unknown how long it takes for a visitor to become an ulthel. Nevertheless, some individuals continue to visit Ulthel, either viewing it as a gold mine of secrets and wealth or seeing the ulthelim's transformation as a utopia.