Tidal Moon
A Ganymede cree collector foils a corporate theft.
"Tidal Moon" is a science fiction short story by American writer Stanley G. Weinbaum and Helen Weinbaum that first appeared in the December 1938 issue of Thrilling Wonder Stories. It is notable as the only story by Weinbaum to take place on Ganymede, and for being completed by his sister Helen after Stanley completed only a page and a half before his death.
Quick Facts
- Author
- Stanley G. Weinbaum and Helen Weinbaum
- Country
- United States
- Language
- English
- Genre
- Science fiction
- Publication Type
- Periodical
- Published In
- Thrilling Wonder Stories
- Publisher
- Thrilling Publications
- Media Type
- Print (Magazine)
- Pub Date
- December 1938
Facts from the source article.
Lore & Background
In Weinbaum's Solar System, Jupiter radiates enough heat to create Earthlike environments on the Galilean moons. Ganymede has a subarctic climate, large bodies of water, and a six-month rotation period. Due to Jupiter's tidal pull, every spot on Ganymede's surface is inundated with water every three months except a small area of the south pole where the human settlement of Hydropole is located. The Ganymedian natives, the Nympus, grow a mosslike plant called cree which is ordinarily red, but turns blue when exposed to ammonia in Ganymede's atmosphere. Blue moss is collected by human traders in the employ of Cree, Inc. who travel among native villages on an aquatic riding animal called a hipp (short for Hippocampus catamiti); it is then shipped to Earth to produce crephine, a combined anaesthetic and medicine. Other Ganymedian life-forms include the whale-like Gamma Rorqual, the tentacled land leet, and the four-winged Blanket Bat.
Reader's Guide
The story's significance lies in its depiction of a corporate espionage plot set against the unique tidal ecology of Ganymede. The plot hinges on the theft of a distillation process for crephine from red moss, which is foiled because the process requires an extract from the eggs of Ganymedian gall-ants, which can only breed on Ganymede. This detail underscores Weinbaum's worldbuilding, where local biology creates economic monopolies. The story also reflects the collaborative effort of the Weinbaums, with Sam Moskowitz noting that Stanley completed only a page and a half before his death, and Helen finishing the story. As the only Weinbaum story set on Ganymede, it contributes to his broader vision of a habitable Jovian system. The narrative includes a flood tide that drowns the village of Aquia, and a chase across the half-flooded surface, culminating in the escape of the thief via a rocket ship colored Ionian red.
More in Moons of Jupiter, Part 2 1-24
Spotted an error? Know more?
Reader corrections go straight into our review queue. Suggest an edit · How this site is sourced