Solaris is a 1961 science fiction novel by Stanisaw Lem about humans' interactions with an unexplainable planet that is itself a single sentient organism. Kris Kelvin arrives aboard the Solaris Station, a space station above the planet, to find only two surviving crew members, Snaut and Sartorius. After aggressive experiments, the planet has begun reproducing clones from their painful past, including Kelvin's wife, Harey, who killed herself. The novel deals with themes of alienation, memory and the nature of human identity and consciousness.