Eesossas

Eesossas is a fictional planet featured in the science fiction novel "Project Hail Mary" by Andy Weir. It is a celestial body that orbits the star Talos, located in the Cygnus constellation. The planet is notable for its unique ecosystem and the presence of an indigenous sentient species.

The surface of Eesossas is characterized by its dim, red sunlight due to Talos being a red dwarf star. This has led to the evolution of life forms adapted to low-light conditions. The planet's atmosphere is rich in nitrogen and contains a significant amount of methane, which contributes to its characteristic orange haze. Eesossas experiences a relatively stable climate, though it is subjected to periods of intense stellar flares from Talos.

The dominant life form on Eesossas are the Eels, a sentient species that resembles terrestrial eels but possesses advanced intelligence and complex social structures. They communicate through bioluminescent patterns and a sophisticated system of pheromones. The Eels have developed a symbiotic relationship with the planet's flora, particularly the "Astrophage," a microorganism that plays a crucial role in their biosphere and the novel's central plot. Eesossas serves as the origin point of the Astrophage, which poses an existential threat to Earth's sun. The novel's protagonist, Ryland Grace, travels to Eesossas on a mission to find a way to combat this threat.