Solaris, written by Stanislaw Lem, is a philosophical science fiction novel that explores the mysteries of an alien planet called Solaris. The story follows psychologist Kris Kelvin, who arrives on a space station orbiting Solaris to study the planet's unique ocean that exhibits sentient behavior. As Kelvin delves deeper into his research, he encounters strange phenomena and confronts his own inner demons. Solaris is a thought-provoking exploration of the limits of human understanding and the complexities of communication with an alien intelligence.