Kahje is the homeworld of the hanar.
With 90% of its surface covered by a vast ocean known as the Encompassing, Kahje is permanently enveloped in a blanket of clouds created by the heat from its energetic white star. Beneath that cloud cover, the planet's land area consists solely of small islands. Kahje's atmosphere is perfect for life; while containing some traces of ammonia, it consists primarily of oxygen, hydrogen, and nitrogen, similar to that on Earth. Unfortunately, the climate has also proved too humid for the non-native drell, who were evacuated there from their own dying homeworld by the hanar two centuries earlier, and they have found it more tolerable to live in climate-controlled domed cities.
Kahje is also dotted with Prothean ruins, which has shaped the religion and society of the hanar. Mount Vassla, an underwater volcano, is at the heart of one of the largest Prothean ruins. The winners of the religious events of the hanar holiday of Nyahir (or "First Cresting Bloom") are inscribed in bioluminescence on the sides of the mountain for a year afterward.
Mass Effect: Homeworlds
Liara T'Soni travels to Kahje seeking a way to stop the Reapers from the planet's Prothean archives. At a submerged Prothean site that the hanar used as a shrine, she discovers a lead: a set of encryption keys that accesses archives on other planets, including Mars.
Mass Effect 3
During an investigation of a hanar diplomat in 2186, if Shepard fails to stop the indoctrinated hanar diplomat Zymandis from sabotaging Kahje's automated planetary defense systems, the planet will be quickly overrun and decimated by Reaper forces. If Shepard succeeds, they manage to save the planet and get the hanar and drell fleet.
Kahje is the terminus of an Illium-Kahje shipping lane.
Known plant life on the water world includes the lerian. It's a bioluminescent sea fern with small pods.
The domed Cnidaria City is the only place on Kahje where drell can live without immediately succumbing to Kepral's Syndrome. One drell's recollections on the place depicts it as a crime-infested slum akin to a noir setting.
- Cnidaria is an animal phylum composed of, among others, jellyfish.