Vísiris

Vísiris is a fictional celestial body featured in the science fiction novel "Project Hail Mary" by Andy Weir. In the narrative, Vísiris is a gas giant planet located in the Tau Ceti star system. It plays a crucial role in the story's plot as the home of the Taumoeba, an alien microorganism that is the key to solving the problem of global warming on Earth.

The Vísiris system is described as being much warmer than Earth's solar system, with Vísiris itself possessing a dense atmosphere and a strong gravitational pull. The Taumoeba, which feed on atmospheric nitrogen and produce oxygen as a byproduct, are uniquely adapted to the conditions of Vísiris. The novel details the efforts of the protagonist, Ryland Grace, to travel to Vísiris, collect samples of the Taumoeba, and bring them back to Earth. The challenges and scientific endeavors involved in this mission form a significant part of the book's plot. Vísiris, therefore, serves as both a vital setting and a source of the story's central conflict and resolution.