Edited by Allan Kaster

An unabridged collection spotlighting the best hard science fiction stories and novellas published in 2023 by current and emerging masters of the genre.

• “The Last Cathedral of Earth, In Flight” by Tobias S. Buckell — The last of humanity flees, among the stars, from alien Prowlers.

• “The Unpastured Sea” by Gregory Feeley — A mission to the planet Neptune runs into many setbacks.

• “The Tinker and the Timestream” by Carolyn Ives Gilman — Colonists on a planet orbiting a decaying sun encounter interstellar time travelers.

• “Six Incidents of Evolution Using Time Travel” by Derek Künsken — Time travel is found to be encoded in the DNA of some alien species.

• “Cloudskimmer” by Geoffrey A. Landis — Robots and humans team up to explore Venus.

• “Even if Such Ways Are Bad” by Rich Larson — A two-person crew goes on a deep space mission inside a living wormship.

• “The Enthnomusicology of the Last Dreadnaught by Yoon Ha Lee — The battle glory of an atrocious weapon of war is honored.

• “Exiled to Gravity” by Marissa Lingen — A mysterious ailment hampers an engineer’s return to space.

• “Clockwork Melting by James Maxey — An immortal races against time to complete an ice sculpture on Venus.

•  “The Elephant Maker” by Alec Nevala-Lee — Scientists clash with hunters and poachers for a rogue elephant needed to test a brain implant.

• “The Ghosts of Mars” by Dominica Phetteplace — A teenager struggles to survive on Mars amidst peculiar phenomena attributed to ghosts.

• “The Many Different Kinds of Love” by Geoff Ryman with David Jeffrey — After ten years of silence, an abiotic intelligence on Enceladus receives unauthorized messages from Earth.

• “Lemuria 7 Is Missing” by Allen M. Steele — The disappearance of a passenger moonship is scrutinized.

• “Defective” by Peter Watts — A zero-sum battle for survival rests on the ability of a scientist to communicate with an alien species.

• “OCASTA” by Daniel H. Wilson — An AI, with an algorithm that analyzes and learns, has a story to tell.