The world of Rakhat
The principles were the same: form follows function, reach high for sunlight, strut your stuff to attract a mate, scatter lots of offspring or take good care of a precious few, warn predators that you’re poisonous with bright colors or blend into the background to escape detection.
Located in the Alpha Centauri solar system, 4.37 light years from Earth, Rakhat has 3 suns and of mass slightly smaller than Earth, so weaker gravity made humans stronger than they were on Earth. The technology on Rakhat is comparable to 19th century Earth, on account of the radio waves signals that were picked up on Earth. The air, water, soil and vegetation are like earth; the flora and fauna follow similar paths of evolution, growth and society.
By far, one of the memorable subjects of The Sparrow is the relationship between the Jana'ata & the Runa - the two major animal species on Rakhat. The Jana'ata are the dominant of the two; they are carnivores, have better technology and live in a complex social organization which evolved in context of cooperative hunting. The author has compared the relationship between these two alien species to the symbiotic relationship between cheetahs and gazelles.
The Runa are more numerous than the Jana'ata but vegetarian, docile, sleek, fur covered and feline. They are traders, and good with languages. They also have a sophisticated practice of raising a child jointly with a trading delegation, learning the new language and cementing the relationship for generations. The Runa are intertwined in Jana'ata life, playing the parts of servants, labourers, assistants and bookkeepers. The Jana'ata also breed the Runa to serve as concubines, given the strict population controls in Jana'ata society (only the first two children in a Jana'ata family are allowed to breed and have families of their own).
The interstellar mission was undertaken in secret and ended in tragedy. Just one member - the linguist Father Emilio Sandoz - survived despite having been physically and psychologically broken down on Rakhat. The circumstances that lead to this anthropological undertaking turning into a nightmare are revealed in the course of the book. The suspense of the story is established when 'what happened' becomes known early on, but 'how it happened' is revealed slowly, and completely only at the end.
The ideas of the story are big, but it is narrated almost throughout with context to interpersonal relationships - among the crew of the Stella Maris, and also with context to cultural differences in the way life and society have emerged on Rakhat. In later interviews the author compared the mutilation of Father Emilio Sandoz with foot-binding procedures prevalent in Japan at one time. The author also narrated how the arrival of the crew of the Stella Maris on Rakhat played into one of the Janatas quest against cultural population control measures.
The title refers to the gospel of Matthew which says that not even a sparrow falls to the ground without God's knowledge - which is strange because in the afterward MDR - who grew up Christian, then veered towards atheism, then moved back towards Christianity when her son was born and finally converted to Judaism - says that Jews know better than people of most other faiths that God does not take an active role in the affairs of men. The Sparrow won the Arthur C. Clarke award and bunch of other awards as well, and is widely acclaimed in sci-fi circles, but doesn't seem to we widely known outside. It is accepted as science fiction but delves deep into religion and topics concerning God.