Which 1950 C.S. Lewis work is a science-fiction novel set partly on Mars?

Out of the Silent Planet is C.S. Lewis’s 1950 science-fiction novel set partly on Mars. It is the first book of his Space Trilogy, followed by Perelandra and That Hideous Strength.

The protagonist, Elwin Ransom, is a Cambridge philologist who is kidnapped and taken aboard a spacecraft by the physicist Weston and his associate Devine. The destination is Malacandra, the planet humans call Mars. There Ransom encounters intelligent species and learns that Earth is known as Thulcandra, the “silent planet,” because it has become spiritually cut off from the wider harmony of the solar system.

Lewis drew on medieval cosmology, Christian theology, and the tradition of planetary romance. The novel challenges the assumption that technological expansion automatically represents moral progress. Weston’s imperial ambitions contrast with Ransom’s growing understanding of Malacandrian culture and language.

Readers sometimes identify Perelandra as the Mars book because it is the second volume and continues Ransom’s interplanetary journey. Perelandra is set on Venus, while Out of the Silent Planet is the installment that takes Ransom to Mars.