Held up on watching the movie, and wanted the read the story first hand from the book (lesson after they butchered the martian ending in the movie)

A single-celled organism which drifts in from interstellar space and starts eating the energy of sun, climatologists predict half of humanity will die in 19 years.

They send out a suicidal interstellar mission to find what is the solution to kill or halt this organism

The rest of the book is heaven for science lovers it covers concepts like mechanics, engineering, time dilation, thermodynamics, evolution, panspermia, mathematics, material science for interstellar space travel. Every chapter sparks your curiosity on what happens next.

Emphasis on what countries can achieve when humanity is in danger, and how everyone can collaborate to make a multi-trillion dollar space mission possible — from nuking antartic ice, covering sahara desert with black panel breeders, making base at chinese aircraft carrier.

And also a deep friendship, and how organisms can step to any level to help each other (organismanity? — cant call it humanity)

A curious and interesting read, definitely recommended