Alan Kaster, who self-publishes several annual thematic reprint anthologies, announced The Year’s Top Hard Science Fiction Stories 6 is available for pre-order. The release date is June 17.

•  “Light up the Clouds” by Greg Egan — Inhabitants in the floating forests of a gas giant that orbits a dwarf star launch a glider on an orbital trajectory to investigate unnatural asteroid-like objects that threaten their survival.
• “Striding the Blast” by Gregory Feeley — As a form of punishment, a thief is forced by posthumans to race on a set of wings across a cloud-covered Mercury.
• “Little Animals” by Nancy Kress — Using entangled quantum effects, a researcher goes back in time and unexpectedly becomes immersed in the life of the daughter of Antonj van Leeuwenhoek.
• “Flowers Like Needles” by Derek Künsken — A metallic crablike creature living on a planet orbiting a pulsar confronts other warriors in its quest for wisdom.
• “The Planetbreaker’s Son” by Nick Mamatas — Interstellar posthuman emigrants, on a starship the size of a football stadium, grapple with vessel maintenance and family preservation while destroying worlds.
• “Paley’s Watch” by Anil Menon — Fishermen find a peculiar artifact in the Gulf of Alaska that is older than Earth and models the structure of the universe.
• “The Metric” by David Moles — A billion-year-old ship delivers a message to a far-future Earth that could mean the destruction of space and time.
• “Año Nuevo” by Ray Nayler — Listless aliens, resembling oversized plastic garbage bags, suddenly disappear thirty years after arriving on a California beachfront.
• “Vaccine Season” by Hannu Rajaniemi — A boy ventures out to an island to inoculate his secluded grandfather with a transmissible vaccine in a post-pandemic future.
• “Submergence” by Arula Ratnakar — An investigator uncovers the exploitation of an unusual marine sponge while optogenetically accessing the memories of a scientist who died unexpectedly.
• “Aptitude” by Cooper Shrivastava— A woman from a slowly dying universe finds herself having to take a rigorous standardized exam after cheating her way into the selection process to become a universe builder.
• “The Egg Collectors” by Lavie Tidhar — Two wild ballooners, forced to land during an ice storm, discover humming black eggs melting into the ice of Titan’s Ligeia Mare.